Assault Weapons and Large-Capacity Magazines

This page collects resources for defending laws that regulate assault weapons and large-capacity magazines against Second Amendment challenges—including a selection of cases, briefs, historical laws, academic articles, and social science. Additional resources will be added over time. Historical laws are also available at the Repository of Historical Gun Laws at Duke Law School. Please get in touch with any questions you might have about these resources, methodology in Second Amendment cases, or any other issues you confront in defending gun safety laws.

A selection of expert witnesses, unaffiliated with Everytown, who have provided evidence in cases defending assault weapon and large-capacity magazine restrictions against Second Amendment challenges is available here.

Cases

Supreme Court

The Supreme Court has granted certiorari in two Second Amendment challenges to restrictions on assault weapons, Viramontes v. Cook County and Grant v. Higgins. These cases are consolidated, with the following Question Presented: “Whether the Second and Fourteenth Amendments guarantee the right to possess AR-15 platform and similar semiautomatic rifles.”

Court of Appeals

The following is a selection of significant appellate decisions since the Supreme Court’s 2022 ruling in New York State Rifle & Pistol Ass’n v. Bruen, 597 U.S. 1 (2022), involving Second Amendment challenges to laws restricting assault weapons and/or large-capacity magazines:

1. Barnett v. Raoul, 180 F.4th 1035, No. 24-3060, 2026 WL 1982951 (7th Cir. July 9, 2026)
   • Issue: challenge to Illinois law restricting assault weapons and large-capacity magazines over 10 rounds (long guns) and over 15 rounds (handguns)
   • Procedural posture: consolidated appeals from declaratory judgment and permanent injunction in favor of plaintiffs after bench trial
   • Holding: Illinois’s law upheld because:
     • Plaintiffs failed to satisfy the facial challenge standard; and 
     • The restrictions satisfy Bruen–Rahimi historical inquiry because “legislatures have long imposed restrictions on particularly dangerous weapons,” including Bowie knives
2. Ass’n of N.J. Rifle & Pistol Clubs, Inc. v. Att’y Gen. New Jersey, — F.4th —-, No. 24-2415, 2026 WL 2075513 (3d Cir. July 17, 2026) (en banc)
   • Issue: challenge to New Jersey laws restricting assault weapons and large-capacity magazines over 10 rounds
   • Procedural posture: consolidated appeals from order granting in part and denying in part cross-motions for summary judgment
   • Holding: The restrictions on semi-automatic rifles and large-capacity magazines over 10 rounds violate the Second Amendment, because they restrict arms covered by the Second Amendment’s text and are inconsistent with the nation’s historical tradition of regulation. Plaintiffs’ challenge regarding other items covered by the laws is remanded to the district court for further proceedings
3. National Ass’n for Gun Rights v. Lamont, 153 F.4th 213 (2d Cir. 2025), cert. granted in part sub nom. Grant v. Higgins, No. 25-566 (June 30, 2026), No. 25-421 (Oct. 3, 2025) (assault weapons and large-capacity magazines)
   • Issue: challenge to Connecticut laws restricting assault weapons and large-capacity magazines over 10 rounds
   • Procedural posture: appeal from denial of preliminary injunction
   • Holding: Connecticut’s laws upheld because:
     • At history step of Bruen-Rahimi analysis, it is consistent with the nation’s longstanding traditions of restricting “novel weapons that are particularly suited for criminal violence” and  “unusually dangerous weapons of their day;” and
     • Plaintiffs failed to establish non-merits requirements for preliminary injunction
4. Capen v. Campbell, 134 F.4th 660 (1st Cir. 2025) (assault weapons and large-capacity magazines)
   • Issue: challenge to Massachusetts laws restricting assault weapons and large-capacity magazines over 10 rounds
   • Procedural posture: appeal from denial of preliminary injunction
   • Holding: Massachusetts’s law upheld at history step of Bruen-Rahimi analysis because:
     • Massachusetts’s assault weapon prohibition continues tradition of “protect[ing] the public from the danger caused by weapons that create a particular public safety threat,” including historical regulations of Bowie knives, sawed-off shotguns, and machine guns; and
     • Challenge to Massachusetts’s large-capacity magazine restriction is foreclosed by Ocean State Tactical, LLC v. Rhode Island, 95 F.4th 38 (1st Cir. 2024)
5. Duncan v. Bonta, 133 F.4th 852 (9th Cir. 2025) (en banc), petition for cert. filed, No. 25-198 (Aug. 15, 2025) (large-capacity magazines)
   • Issue: challenge to California law restricting large-capacity magazines over 10 rounds
   • Procedural posture: appeal from order granting summary judgment to plaintiffs, denying summary judgment to California, and entering permanent injunction
   • Holding: California’s law is constitutional because:
     • It is consistent with the Second Amendment at both steps of the Bruen–Rahimi analysis:
       • At text step, “large-capacity magazines are neither weapons nor accessories that are necessary to the operation of a weapon,” and thus “the Second Amendment’s plain text does not protect [their] possession”;
       • At history step, California’s law fits within the nation’s historical traditions of “protecting innocent persons by restricting a component necessary to the firing of a firearm and by restricting especially dangerous uses of weapons when those uses have proved particularly harmful”; and
     • Plaintiffs’ Takings Clause challenge also fails
6. Hanson v. District of Columbia, 120 F.4th 223 (D.C. Cir. 2024), cert. denied, 145 S. Ct. 2778 (2025) (large-capacity magazines)
   • Issue: challenge to D.C. law restricting large-capacity magazines over 10 rounds
   • Procedural posture: appeal from denial of preliminary injunction
   • Holding: D.C.’s law upheld because:
     • At history step of Bruen-Rahimi analysis, it is consistent with the nation’s history and tradition of regulating weapons that are “particularly dangerous,” “particularly capable of unprecedented lethality,” or “that are particularly susceptible to, and were widely used for, multiple homicides and mass injuries”; and
     • Plaintiffs failed to establish non-merits requirements for preliminary injunction
7. Bianchi v. Brown, 111 F.4th 438 (4th Cir. 2024) (en banc), cert. denied, 145 S.Ct. 1534 (2025) (assault weapons)
   • Issue: challenge to Maryland law restricting assault weapons
   • Procedural posture: appeal from order dismissing complaint
   • Holding: Maryland’s law is constitutional at both text and history steps of Bruen-Rahimi analysis because:
     • Assault weapons are “military-style weapons” that are “ill-suited and disproportionate to the need for self-defense” and thus fall outside the scope of the Second Amendment; and
     • Maryland’s law also adheres to our nation’s “strong tradition of regulating excessively dangerous weapons”
8. Delaware State Sportsmen’s Ass’n v. Delaware Department of Safety & Homeland Security, 108 F.4th 194 (3d Cir. 2024), cert. denied, 145 S. Ct. 1049 (2025) (assault weapons and large-capacity magazines)
   • Issue: challenge to Delaware laws restricting assault weapons and large-capacity magazines over 17 rounds
   • Procedural posture: appeal from denial of preliminary injunction
   • Holding: Plaintiffs were not entitled to a preliminary injunction because they failed to establish irreparable harm and other non-merits requirements for preliminary injunction; did not reach merits of Second Amendment claims
     • In a concurring opinion, Judge Roth explained that she also would have rejected plaintiffs’ challenge on the merits, at both text and history steps of Bruen-Rahimi analysis
9. Ocean State Tactical, LLC v. Rhode Island, 95 F.4th 38 (1st Cir. 2024), cert. denied, 145 S. Ct. 2771 (2025) (large-capacity magazines)
   • Issue: challenge to Rhode Island law restricting large-capacity magazines over 10 rounds
   • Procedural posture: appeal from denial of preliminary injunction
   • Holding: Rhode Island’s law upheld because:
     • At history step of Bruen analysis, it is consistent with the nation’s history and tradition, including “the historical regulation of gunpowder storage and of weapons like sawed-off shotguns, Bowie knives, M-16s, and the like”; and
     • Plaintiffs’ Takings Clause and due process retroactivity and vagueness challenges also fail
10. Bevis v. City of Naperville, 85 F.4th 1175 (7th Cir. 2023), cert. denied, 144 S. Ct. 2491 (2024) (assault weapons and large-capacity magazines)
    • Issue: challenges to Illinois law restricting assault weapons and large-capacity magazines over 10 rounds (long guns) and over 15 rounds (handguns) and similar local ordinances
    • Procedural posture: consolidated appeals from denials and grant of preliminary injunction
    • Holding: Illinois’s law and local ordinances upheld at both text and history steps of Bruen analysis because:
      • Plaintiffs failed to show that assault weapons and large-capacity magazines “are Arms that ordinary people would keep at home for purposes of self-defense, not weapons that are exclusively or predominantly useful in military service, or weapons that are not possessed for lawful purposes”; and
      • Challenged state and local laws are also consistent with the nation’s history and tradition of restricting civilian access to “the especially dangerous weapons of the time”
    • Note: See also Viramontes v. County of Cook, No. 24-1437, 2025 WL 1553896 (7th Cir. June 2, 2025) (nonprecedential), petition for cert. filed, No. 25-238 (Aug. 27, 2025) (affirming grant of summary judgment to Cook County in challenge to local assault weapon restriction because challengers “failed to develop a record sufficient to justify a different result” than Bevis)
11. State of Washington v. Gator’s Custom Guns, Inc., 568 P.3d 278 (Wash. 2025) (en banc), petition for cert. filed, No. 25-153 (Aug. 6, 2025) (large-capacity magazines)
    • Issue: challenge to Washington law restricting large-capacity magazines over 10 rounds
    • Procedural posture: appeal from order granting summary judgment to plaintiffs and denying summary judgment to Washington
    • Holding: Washington’s law is constitutional because:
      • It is consistent with the Second Amendment at the text step of the Bruen-Rahimi analysis:
        • Large-capacity magazines are accessories that modify a weapon’s ammunition capacity, “not instruments designed as weapons”;
        • Large-capacity magazines are not commonly used for self-defense; and
        • There is no ancillary Second Amendment right to purchase large-capacity magazines 
      • Also no violation of right to bear arms under Washington Constitution

Additional appeals are pending, including the following:

1. Vermont Federation of Sportsmen’s Clubs v. Birmingham, No. 24-2026 (2d Cir.) (large-capacity magazines)
   • Issue: challenge to Vermont law restricting large-capacity magazines over 10 rounds (long guns) and over 15 rounds (handguns)
   • Procedural posture: appeal from denial of preliminary injunction
   • Status: oral argument not yet scheduled
2. Miller v. Bonta, No. 23-2979 (9th Cir.) (assault weapons)
   • Issue: challenge to California law restricting assault weapons
   • Procedural posture: appeal from final judgment and permanent injunction in favor of plaintiffs
     • Ninth Circuit stayed district court judgment and injunction pending appeal or further order of the court
   • Status: oral argument held January 24, 2024; held in abeyance pending resolution of Duncan v. Bonta, No. 23-55805; supplemental briefs addressing the impact of Duncan filed April 24, 2025; supplemental briefs addressing the impact of United States v. Kittson, 161 F.4th 619 (9th Cir. 2025) (upholding federal restriction on machinegun transfer or possession), filed January 12, 2026
3. Rupp v. Bonta, No. 24-2583 (9th Cir.) (assault weapons)
   • Issue: challenge to California law restricting assault weapons
   • Procedural posture: appeal from order granting summary judgment to California and denying summary judgment to plaintiffs
   • Status: stayed pending resolution of Duncan v. Bonta, No. 23-55805
4. Banta v. Ferguson, No. 24-6537 (9th Cir.) (assault weapons)
   • Issue: challenge to Washington law restricting assault weapons
   • Procedural posture: appeal from denial of preliminary injunction
   • Status: stayed pending resolution of Duncan v. Bonta, No. 23-55805, and Miller v. Bonta, No. 23-2979
5. Fitz v. Rosenblum, Nos. 23-35478, 23-35479, 23-35539, 23-35540 (9th Cir.) (large-capacity magazines)
   • Issue: challenge to Oregon law restricting large-capacity magazines over 10 rounds
   • Procedural posture: consolidated appeals from final judgment in favor of Oregon after bench trial
   • Status: stayed pending resolution of Duncan v. Bonta, No. 23-55805

Selected Briefs

Everytown Law represents governments defending gun safety laws against Second Amendment challenges, including in cases involving restrictions on assault weapons and/or large-capacity magazines. In addition, Everytown’s amicus briefs in assault weapon and large-capacity magazine cases are available here (assault weapons) and here (large-capacity magazines).

The following is a selection of recent government briefs in key assault weapons and large-capacity magazine cases, along with links to the dockets.

1. Rocky Mountain Gun Owners v. Town of Superior (D. Colo.) (assault weapons and large-capacity magazines)
   • Colorado localities’ statement of supplemental authority (Aug. 16, 2024)
   • Colorado localities’ renewed summary judgment brief (Sept. 5, 2025)
   • Colorado localities’ renewed summary judgment reply brief (Oct. 24, 2025)
   • District Court docket
2. Barnett v. Raoul (S.D. Ill./7th Cir.) (assault weapons and large-capacity magazines)
   • Illinois’s reply brief (7th Cir. Aug. 14, 2025)
   • Illinois’s opening brief (7th Cir. May 7. 2025) (post-trial appeal)
   • Illinois’s post-trial proposed findings of fact (S.D. Ill. Oct. 21, 2024)
   • Illinois’s post-trial proposed conclusions of law (S.D. Ill. Oct. 21, 2024)
   • Illinois’s opening brief (7th Cir. June 5, 2023) (preliminary injunction appeal)
   • Illinois’s reply brief (7th Cir. June 26, 2023) (preliminary injunction appeal)
   • Court of Appeals docket (post-trial appeal)
   • Court of Appeals docket (preliminary injunction appeal)
   • District Court docket
3. Association of New Jersey Rifle & Pistol Clubs v. Attorney General New Jersey (D.N.J./3d Cir.) (assault weapons and large-capacity magazines)
   • New Jersey’s opening brief (3d Cir. Jan. 8, 2025)
   • New Jersey’s reply brief (3d Cir. Feb. 28, 2025)
   • New Jersey’s summary judgment brief (D.N.J. Nov. 3, 2023)
   • New Jersey’s summary judgment reply brief (D.N.J. Jan. 19, 2024)
   • Court of Appeals docket
   • District Court docket
4. Lane v. Cacace (S.D.N.Y.) (assault weapons)
   • New York’s summary judgment brief (May 15, 2024)
   • New York’s summary judgment reply brief (Aug. 2, 2024)
   • District Court docket
5. Miller v. Bonta (9th Cir.) (assault weapons)
   • California’s opening brief (Dec. 1, 2023)
   • California’s reply brief (Jan. 8, 2024) 
   • Court of Appeals docket
6. Duncan v. Bonta (9th Cir.) (en banc) (large-capacity magazines)
   • California’s opening brief (Nov. 21, 2023)
   • California’s reply brief (Jan. 25, 2024)
   • Court of Appeals docket
7. Hanson v. District of Columbia (D.C. Cir.) (large-capacity magazines)
   • District of Columbia’s brief (Oct. 2023)
   • Court of Appeals docket
8. Rupp v. Bonta (C.D. Cal.) (assault weapons)
   • California’s summary judgment brief (May 26, 2023)
   • California’s summary judgment opposition brief (June 23. 2023)
   • California’s summary judgment reply brief (July 14, 2023)
   • Court of Appeals docket
   • District Court docket
9. Oregon Firearms Federation v. Kotek (D. Or.) (large-capacity magazines)
   • Oregon’s trial brief (May 15, 2023)
   • Court of Appeals docket
   • District Court docket

Historical Laws

Restrictions on Automatic and Semiautomatic Firearms

1. West Virginia: 1925 W.Va. Acts 31-32, ch. 3, § 7(b) (prohibiting the carry, transport, or possession of “any machine gun, sub-machine gun, and … high powered rifle” with exceptions for private property, license holders, or bona fide rifle club members) [HeinOnline]
2. California: 1927 Cal. Stat. 938, ch. 552, §§ 1-2 (prohibiting possession of “all firearms known as machine rifles, machine guns or submachine guns capable of discharging automatically and continuously loaded ammunition of any caliber in which the ammunition is fed to such gun from or by means of clips, disks, drums, belts or other separable mechanical device”) [HeinOnline]
3. Indiana: 1927 Ind. Acts 469, ch. 156, § 1 (prohibiting the possession or ownership of machine guns) [HeinOnline]
4. Iowa: 1927 Iowa Acts 201, §§ 1-2 (prohibiting possession of “any machine gun which is capable of being fired from the shoulder or hip of a person, and by the recoil of such gun”) [HeinOnline]
5. Massachusetts: 1927 Mass. Acts 413-16, ch. 326, §§ 1-5 (creating prohibitive licensing for machine guns defined as “[a]ny gun of small arm calibre designed for rapid fire and operated by a mechanism, or any gun which operates automatically after the first shot has been fired, either by gas action or recoil action”) [HeinOnline]
6. New Jersey: 1927 N.J. Laws 180-81, ch. 95, §§ 1-2 (prohibiting any “machine gun or automatic rifle” defined to include “any weapon, mechanism or instrument not requiring that the trigger be pressed for each shot and having a reservoir, belt or other means of storing and carrying ammunition which can be loaded into the said weapon, mechanism or instrument and fired therefrom at a rate of five or more shots to the second”) [HeinOnline]
7. Rhode Island: 1927 R.I. Pub. Laws 256-57 (prohibiting the manufacture, sale, purchase, or possession of any “machine gun” defined to include “any weapon which shoots automatically and any weapon which shoots more than twelve shots semi-automatically without reloading”) [HeinOnline]
8. Michigan: 1927 Mich. Pub. Acts 888-89 (prohibiting the manufacture, sale, and possession of “any machine gun or firearm which can be fired more than sixteen times without reloading”) [HeinOnline]
9. Model Law: Report of Firearms Committee, Handbook of the National Conference on Uniform State Laws and Proceedings of the Thirty-Eighth Annual Meeting 422, 428 (1928) (prohibiting possession of any “machine gun” defined as “any firearm which shoots automatically and any firearm which shoots more than twelve shots semi-automatically without reloading”) [HeinOnline]
10. Missouri: 1929 Mo. Laws 170, §§ 1-2 (prohibiting machine guns defined to include “all firearms known as machine rifles, machine guns or sub-machine guns capable of discharging automatically and continuously loaded ammunition of any caliber in which the ammunition is fed to such gun from or by means of clips, disks, drums, belts or other separable mechanical device”) [HeinOnline]
11. Nebraska: 1929 Neb. Laws 674, ch. 190, §§ 1-2 (prohibiting the sale, disposition, transport, or possession of machine guns, with exceptions for law enforcement, U.S. Army, and National Guard) [HeinOnline]
12. Pennsylvania: 1929 Pa. Laws 777, §§ 1-2 (prohibiting the possession or sale of any “machine gun” defined as “any firearm that fires two or more shots consecutively at a single function of the trigger or firing device”) [HeinOnline]
13. Wisconsin: 1929 Wis. Sess. Laws 157, ch. 132, § 1 (prohibiting any person to “own, use or have in his possession a machine gun”) [HeinOnline]
14. Arkansas: 1931 Ark. Acts 705-06, §§ 1-3 (prohibiting the transfer, sale, or possession of “any firearm of the type commonly known as a machine gun”) [HeinOnline]
15. Delaware: 1931 Del. Laws 813, ch. 249, § 1 (“[I]t is and shall be unlawful for any person or persons other than the State Military Forces or duly authorized Police Departments to have a machine gun in his or their possession[.]”) [HeinOnline]
16. Illinois: 1931 Ill. Laws 452-53, §§ 1-2 (prohibiting the possession, sale, manufacture, or transportation of “all firearms commonly known as machine rifles, machine guns and sub-machine guns of any caliber whatsoever, capable of automatically discharging more than eight cartridges successively without reloading, in which the ammunition is fed to such gun from or by means of clips, disks, belts, or other separable mechanical device”) [HeinOnline]
17. North Dakota: 1931 N. D. Laws 305-06, ch. 178, §§ 1-2 (prohibiting possession of “any machine gun, sub-machine gun, [or] automatic rifle of a caliber larger than twenty-two”) [HeinOnline]
18. District of Columbia: H.R. 8754, 72d Cong. §§ 1, 14 (1932) (making it a crime in D.C. to “possess any machine gun” defined as “any firearm which shoots automatically or semiautomatically more than twelve shots without reloading”) [HeinOnline]
19. Louisiana: 1932 La. Acts 337-38, §§ 1-2 (prohibiting the purchase, sale, carry, or possession of “any machine gun” defined to include “all firearms commonly known as machine rifles, machine guns and sub-machine guns of any caliber whatsoever, capable of automatically discharging more than eight cartridges successively without reloading, in which the ammunition is fed to such gun from or by means of clips, disks, belts, or other separable mechanical device”) [HeinOnline]
20. California: 1933 Cal. Stat. 1170, § 3 (prohibiting the sale or possession of “machine rifles, machine guns, or submachine guns capable of discharging automatically and continuously loaded ammunition of any caliber in which the ammunition is fed to such gun from or by means of clips, discs, drums, belts or other separable mechanical device and all firearms which are automatically fed after each discharge from or by means of clips, discs, drums, belts or other separable mechanical device having a capacity greater than ten cartridges”) [HeinOnline]
21. Hawaii: 1933 Haw. Special Sess. Laws 36, 38-39, §§ 2, 7 (prohibiting the possession, manufacture, or sale of “any machine guns, sub-machine guns, automatic rifles”) [HeinOnline]
22. Hawaii: 1933 Haw. Sess. Laws 117, § 2 (prohibiting the possession, manufacture, or sale of “machine rifles, machine guns and submachine guns capable of automatically and continuously discharging loaded ammunition of any caliber in which the ammunition is fed to such guns from or by means of clips, disks, drums, belts or other separable mechanical device”) [HeinOnline]
23. Kansas: 1933 Kan. Sess. Laws 76, ch. 62, §§ 1-2 (prohibiting the possession of any “firearm known as a machine rifle, machine gun, or submachine gun”) [HeinOnline]
24. Minnesota: 1933 Minn. Laws 232-33, ​​ch. 190, §§ 1-3 (prohibiting the possession, sale, or transport of machine guns defined to include “(a) [a]ny firearm capable of loading or firing automatically, the magazine of which is capable of holding more than twelve cartridges …(b) [a]ny firearm capable of automatically reloading after each shot is fired, whether firing singly by separate trigger pressure or firing continuously” if the firearm was modified to allow for a larger magazine capacity, and “(c) A twenty-two caliber light sporting rifle, capable of firing continuously by continuous trigger pressure”) [HeinOnline]
25. New York: 1933 N.Y. Laws 1639, ch. 805, §§ 1, 3 (prohibiting possession, sale, or transport of any “machine gun” defined to include any “sub-machine gun” or any weapon “from which a number of shots or bullets may be rapidly or automatically discharged from a magazine with one continuous pull of the trigger”) [HeinOnline]
26. Ohio: 1933 Ohio Laws 189-90 (creating prohibitive licensing for machine guns “defined as any firearm which shoots automatically, or any firearm which shoots more than eighteen shots semi-automatically without reloading”) [HeinOnline]
27. Oregon: 1933 Or. Laws 488-89, ch. 315, §§ 1-3 (prohibiting possession of machine guns defined to include any weapon “from which two or more shots may be fired by a single pressure upon the trigger device”) [HeinOnline]
28. South Dakota: 1933 S.D. Sess. Laws 245-47, ch. 206, §§ 1-8 (regulating the possession of machine guns defined to include any weapon “from which more than five shots or bullets may be rapidly or automatically, or semi-automatically discharged from a magazine, by a single function of the firing device”) [HeinOnline]
29. Texas: 1933 Tex. Gen. Laws 219, ch. 82, §§ 1-3 (prohibiting possession or use of any “machine gun” which includes any weapon “from which more than five (5) shots or bullets may be automatically discharged from a magazine by a single functioning of the firing device”) [HeinOnline]
30. Washington: 1933 Wash. Sess. Laws 335-36, ch. 64, §§ 1-2 (prohibiting “any machine gun, or any part thereof” and defining “machine gun” to include “any firearm or weapon known as a machine gun, mechanical rifle, submachine gun, and/or any other weapon, mechanism, or instrument not requiring that the trigger be pressed for each shot and having a reservoir clip, disc, drum belt, or other separable mechanical device for storing, carrying, or supplying ammunition which can be loaded into such weapon, mechanism, or instrument, and fired therefrom at the rate of five or more shots per second”) [HeinOnline] 
31. Wisconsin: 1933 Wis. Sess. Laws 245-47, 778 (prohibiting the selling, use, possession, and transportation of “any machine gun or other full automatic firearm,” and defining “machine gun” to include “a weapon … from which more than two shots or bullets may be discharged by a single function of the firing device”) [HeinOnline]
32. South Carolina: 1934 S.C. Acts 1288 (prohibiting possession of “all firearms commonly known as machine rifles, machine guns and sub-machine guns of any caliber whatsoever, capable of automatically discharging more than eight cartridges successively without reloading, in which the ammunition is fed to such gun from or by means of clips, disks, belts or other separable mechanical device”) [HeinOnline]
33. Virginia: 1934 Va. Acts 137-40 (regulating the possession or use of weapons “from which more than seven shots or bullets may be rapidly, or automatically, or semi-automatically discharged from a magazine, by a single function of the firing device,” and weapons “from which more than sixteen shots or bullets may be rapidly, automatically, semi-automatically or otherwise discharged without reloading”) [HeinOnline]
34. National Firearms Act of 1934: 48 Stat. 1236-1240, 26 U.S.C.A. § 1132 et seq. (imposing registration requirements and restrictions on the possession, sale, and transportation of firearms, including shotguns and rifles having barrels less than 18 inches in length, certain firearms described as “any other weapons,” machine guns, and firearm mufflers and silencers) [HeinOnline]
35. Arkansas: 1935 Ark. Acts 171-75 (creating prohibitive requirements for possession of any “machine gun” defined as “a weapon of any description by whatever name known, loaded or unloaded, from which more than five shots or bullets may be rapidly, or automatically, or semi-automatically discharged from a magazine, by a single function of the firing device”) [HeinOnline]

Serial Number Mandates and Prohibitions on Removing Serial Numbers and Possessing Firearms with Obliterated Serial Numbers

1. Missouri: 1921 Missouri Sess. Laws 691-93 (requiring handguns “have plaintly and permanently stamped upon the metallic portion thereof, the trademark or name of the maker, the model and serial factory number thereof, which number shall not be the same as that of any other such weapon of the same model made by the same maker.”) [HeinOnline]
2. Federal: 26 CFR 85, § 177.50, subpart D, Conduct of Business (1960) – (requiring gun manufacturers to included “in a manner not susceptible of being readily obliterated or altered, the name of the manufacturer or importer, and the serial number[,] caliber, and model of the firearm.”) [HeinOnline]
3. Federal: 82 Stat. 1213, § 922(k), § 923(i).; PL 90-618 (Oct. 22, 1968) – “identify, by means of a serial number engraved or cast on the receiver or frame of the weapon, . . . each firearm imported or manufactured[.]” The GCA also made it a crime to “transport, ship, or receive” a firearm with an obliterated serial number [HeinOnline]
4. California: 1923 Cal. Acts 695, 702, § 13 (“No person shall change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification on any pistol or revolver. Possession of any such firearm upon which the same shall have been changed, altered, removed, or obliterated, shall be presumptive evidence that such possessor has changed, altered, removed or obliterated the same.”) [HeinOnline]
5. Connecticut: 1923 Conn. Sess. Laws 3709, § 11 (“No person shall change, alter, remove or obliterate the name of any maker or model or any makers number or other mark of identification on any pistol or revolver. The possession of any pistol or revolver upon which any identifying mark, number or name shall have been changed, altered, removed or obliterated shall be prima facie evidence that the person owning or in possession of such pistol or revolver has changed, altered, removed or obliterated the same.”) [HeinOnline]
6. North Dakota: 1923 N.D. Sess. Laws 381, § 14 (“No person shall change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification on any pistol or revolver. Possession of any such firearm upon which the same shall have been changed, altered, removed, or obliterated shall be presumptive evidence that such possessor has changed, altered, removed, or obliterated the same.”) [HeinOnline]
7. New Hampshire: 1923 N.H. Acts 138, §12 (“No person shall change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number or other mark of identification on any pistol or revolver. Possession of any such firearms upon which the same shall have been changed, altered, removed or obliterated, shall be presumptive evidence that such possessor has changed, altered, removed or obliterated the same.”) [HeinOnline]
8. Indiana: 1925 Ind. Acts 495 §§ 11, 13 (“No person shall within the State of Indiana change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification. Possession of any such firearms upon which the same shall have been changed, altered, removed, or obliterated, shall be prima facie evidence that such possessor has changed, altered, removed, or obliterated the same.”) [HeinOnline]
9. Michigan: 1925 Mich. Acts 473, §§ 7, 10 (“No person shall deliberately change, alter, remove or obliterate the name of the maker, model, manufacturer’s number or other mark of identity of any pistol, revolver or gun. Possession of any such firearm upon which the name or number shall have been deliberately changed, altered, removed or obliterated shall be presumptive evidence that such possessor has changed, altered, removed or obliterated the same”) [HeinOnline]
10. New Jersey: 1925 N.J. Laws 185, § 6 (“Any person who shall alter, change, disfigure or deface the serial number of any pistol or revolver shall be guilty of a misdemeanor; any person engaged in the retail business of selling, leasing or otherwise transferring pistols, revolvers, or other firearms who shall sell or lease any pistol, or revolver having the serial number thereof altered, changed, disfigured or defaced shall be guilty of a misdemeanor”) [HeinOnline]
11. Hawaii: 1927 Haw. Acts 209, 211-212 (“No person shall change, alter, remove, or obliterate the name of the maker, model, manufacturers number or other mark of identification on any pistol or revolver. Possession of any pistol or revolver upon which any such mark shall have been changed, altered, removed, or obliterated, shall be prima facie evidence that the possessor has changed, altered, removed or obliterated the same.”) [HeinOnline]
12. Pennsylvania: 1931 Penn. Acts 497, 499, § 15 (“No person shall change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification on any firearm. Possession of any firearm, upon which any such mark shall have been changed, altered, removed, or obliterated shall be prima facie evidence that the possessor has changed, altered, removed or obliterated the same.”) [HeinOnline]
13. South Dakota: 1935 S.D. Laws 355, § 14 (“No person shall change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification on any pistol. Possession of any pistol upon which any such mark shall have been changed, altered, removed, or obliterated, shall be Prima Facie evidence that the possessor has changed, altered, removed or obliterated the same.”) [HeinOnline]
14. Washington: 1935 Wash. Sess. Laws 599, 601 § 14 (“No person shall change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification on any pistol. Possession of any pistol upon which any such mark shall have been changed, altered, removed, or obliterated, shall be prima facie evidence that the possessor has changed, altered, removed, or obliterated the same.”) [HeinOnline]
15. Alabama: 1936 Ala. Sess. Laws 51, 54 § 14 (“no person shall change, alter, remove, or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification of any pistol. Possession of any pistol upon which any such mark shall have been changed, altered, removed, or obliterated, shall be prima facie evidence that the possessor has changed, altered, removed or obliterated the same.”) [HeinOnline]
16. District of Columbia: 47 Stat. 650 § 12 (1932) (“No person shall within the District of Columbia change, alter, remove or obliterate the name of the maker, model, manufacturer’s number, or other mark of identification on any pistol, machine gun, or sawed-off shotgun. Possession of any pistol, machine gun, or sawed-off shotgun upon which any such mark shall have been changed, altered, removed, or obliterated shall be prima facie evidence that the possessor has changed, altered, removed, or obliterated the Same within the District of Columbia.”) [HeinOnline]

Restrictions on Other Weapons, Weapon Features, and Accessories

1. 1670 Plymouth Law (“Whereas severall persons have beee greatly endangered by setting of Guns It is enacted by the Court and the authority thereof that none shall set any guns except in enclosures and that the gun be sufficiently enclosed so as it be secure from hurting man or beast, and that he that seteth the gun doe give warning or notice thereof to all the neighbors on the penalty of paying a fine of five pounds to the use of the colony for every default.”) [Source]
2. New Jersey: 1763-1775 N.J. Laws 346, ch. 539, § 10 (“Whereas a most dangerous Method of getting Guns has too much prevailed…, That if any Person or Persons within this Colony shall presume to set any loaded Gun in such Manner as that the same shall be intended to go off or discharge itself, or be discharged by any String, Rope, or other Contrivance, such Person or Persons shall forfeit and pay the Sum of Six Pounds.”) [HeinOnline]
3. Alabama: 1837 Ala. Laws 7, § 2 (prohibitively taxing bowie knives) [HeinOnline]
4. Georgia: 1837 Ga. Laws 90, § 1 (prohibiting the sale and possession of “Bowie, or any other kinds of knives, manufactured and sold for the purpose of wearing, or carrying the same as arms of offence or defense” as well as “pistols, dirks, sword canes, [and] spears”) [HeinOnline]
5. Tennessee: 1837-1838 Tenn. Pub. Acts 200-01, §§ 1-2 (prohibiting the sale and concealed carry of bowie knives, Arkansas toothpicks, or other similar knives) [HeinOnline]
6. Florida: 1838 Fla. Laws, No. 24, § 1 (prohibitively taxing the sale and possession of pocket pistols, sword canes, or bowie knives) [HeinOnline]
7. New York: 1849 N.Y. Sess. Laws 403, c. 278 An Act to Prevent the Manufacture, Use, and Sale of Slung Shot (prohibiting anyone to “manufacture,” “sell,” “keep for sale or gift,” “part with,” “carry,” “possess,” or “use or attempt to use” a slung shot) [HeinOnline]
8. Vermont: 1849 Vermont Acts 26, No. 36, An Act Prohibiting the Manufacture, Sale, and Use of Slung Shot. (prohibiting anyone to “sell, expose or keep for sale or gift or part with” a slung shot, as well as “carry, or be found in the possession of, use or attempt to use” a slung shot) [HeinOnline]
9. Massachusetts: 1850 Mass. Acts & Resolves 401, ch. 194 (prohibiting the manufacture or sale of slung-shots) [HeinOnline]
10. Kentucky: 1855 Kent. Pub. Acts 96, c. 636, An Act to Prevent the Selling and Using of Certain Weapons (prohibiting “vending, buying, selling or dealing in” slungshots or brass knuckles) [HeinOnline]
11. Dakota Territory: General and Private Laws and Memorials and Resolutions of the Territory of Dakota 128 (1864-65) (punishing anyone who “manufactures or causes to be manufactured, or sells, or offers or keeps for sale; or gives or disposes of any instrument or weapon of the kind usually known as a slung shot.”) [N.D. Legislature]
12. Florida: 1868 Fla. Laws 95, ch. 7, § 11 (prohibiting the manufacture or selling of slung shots or metallic knuckles) [HeinOnline]
13. Minnesota:1869 Minn. Laws 50-51, § 1 (prohibiting “[t]he setting of a so-called trap or spring gun, pistol, rifle, or other deadly weapon”) [HeinOnline]
14. Nashville, Tennessee: John Lellyett, Ordinances of the City of Nashville 244 (1872) (§ 9) (prohibiting any “sling gun, or spring shot, made from India rubber, or other elastic substances, attached to a forked stick, or other brace, to throw or shoot pebbles, gravel, shot, bullets, or other hard substances, or to use a bow and arrow”) [Hathi]
15. Wisconsin: (New) Revised Statutes of the State of Wisconsin ch. 183, § 53 p. 1964 (1872) Any person or persons in this State who shall hereafter set any gun, pistol or revolver, or any other firearms, for the purpose of killing deer or any other game, or for any other purpose, shall be deemed guilty of a misdemeanor, and upon conviction shall be fined in a sum not exceeding fifty dollars, and shall be imprisoned in the county jail of the proper county for a term of not less than twenty days. [HeinOnline]
16. Nevada: Revised Laws of Nevada 1872 (1912) (“6567. Setting Spring Gun. Sec. 302. Every person who shall set a so-called trap, spring pistol, rifle, or other deadly weapon, shall be punished as follows: 1. If no injury result therefrom to any human being, by imprisonment in the county jail for not more than one year or by a fine of not more than one thousand dollars, or by both. 2. If injuries not fatal result therefrom to any human being, by imprisonment in the state prison for not more than twenty years. 3. If the death of a human being results therefrom, under circumstances not rendering the act murder, by imprisonment in the state prison for not more than twenty years, otherwise the punishment shall be as for murder.”) [HeinOnline]
17. New York: 1874 N.Y. Acts 491, c. 390 (“No person shall in any part of this State, set any trap, spring gun or other device at any artificial salt lick or other place, for the purpose of trapping and killing any moose or deer.”) [HeinOnline]
18. Michigan: 1875 Mich. Pub. Acts 136, § 1 (prohibiting the setting of “any spring or other gun, or any trap or device operating by the firing or explosion of gunpowder or any other explosive”) [HeinOnline]
19. Arkansas: 1881 Ark. Acts 191-92 (prohibiting the carry or sale of “any dirk or bowie knife, or a sword, or a spear in a cane, brass or metal knucks, razor, or any pistol of any kind whatever, except such pistols as are used in the army or navy”) [HeinOnline]
20. Illinois: 1881 Ill. Sess. Laws 71 (prohibiting the possession or sale of slung-shots, metallic knuckles, or other deadly weapons of like character) [HeinOnline]
21. New York: 1881 N.Y. Acts vol III 1, 102, sec. 409 (punishing “A person who manufactures, or causes to be manufactured, or sells or keeps for sale, or offers, or gives, or disposes of, any instrument or weapon of the kind usually known as a slung-shot, billy, sand-club, or metal knuckles, is guilty of a misdemeanor.”) [HeinOnline]
22. Wisconsin: 1883 Wisconsin Acts 13, c. 20. (“Section 1. Section 4394 of chapter 181 of the revised statutes of Wisconsin, is hereby amended to read as follows: Any person who shall set or fix in any manner whatever any gun, pistol or other fire-arm, or any spring-gun for the purpose of killing game of any kind by coming in contact therewith, or with any string, wire or other contrivance attached thereto, by which the same may be discharged, or for any other purpose, shall be punished by imprisonment in the state prison not less than six months nor more than three years; and if the death of any person is caused thereby he shall be deemed guilty of manslaughter in the second degree.”) [HeinOnline]
23. Vermont: 1884 Vt. Acts & Resolves 74-75, No. 76, § 1 (“A person who sets a spring gun trap, or a trap whose operation is to discharge a gun or firearm at an animal or person stepping into such trap, shall be fined not less than fifty nor more than five hundred dollars”) [HeinOnline]
24. Minnesota: The Penal Code of the State of Minnesota 127 (1885), Sec. 333 (“A person who manufactures or causes to be manufactured, or sells or keeps for sale, or offers, or gives, or disposes of any instrument or weapon of the kind usually known as a slung-shot, sand-club, or metal knuckles, . . . is guilty of a misdemeanor.”) [HeinOnline]
25. Massachusetts: The Public Statutes of the Commonwealth of Massachusetts 1164 (1886) c. 206, sec. 11 (“Whoever manufactures or causes to be manufactured, or sells or exposes for sale, an instrument or weapons on the kind usually known as slung-shot, or metallic knuckles, shall be punished by fine of not less than fifty dollars, or by imprisonment in the jail not exceeding six months.”)[HeinOnline]
26. Minnesota: The Penal Code of the State of Minnesota, To Take Effect January 1, A.D. 1886, at 127 (1885) (“A person who manufactures or causes to be manufactured, or sells or keeps for sale, or offers, or gives, or disposes of any instrument or weapon of the kind usually known as slung-shot, sand-club, or metal knuckles … is guilty of a misdemeanor.”) [HeinOnline]
27. Oklahoma: 1890 Okla. Sess. Laws 475-76, §§ 18-19 (prohibiting the possession, manufacture, sale, or disposing of slung shots or similar weapons) [HeinOnline]
28. New York: 1893 N.Y. Sess. Laws 1288 (Prohibiting “[m]aking or selling[a] slung-shot or any similar weapon”) [HeinOnline]
29. Florida: 1893 Fla. Sess. Laws 51 (punishing anyone who “manufactures, or causes to be manufactured, or sells or exposes for a sale” a slung shot or brass knuckles) [HeinOnline]
30. North Dakota: The Revised Codes of the State of North Dakota 1259 (1895) (“Every person who sets any spring or other gun or trap or device operating by the firing or exploding of gunpowder or any other explosive, and leaves or permits the same to be left, except in the immediate presence of some competent person, shall be deemed to have committed a misdemeanor[.]”) [Google Books]
31. South Dakota: 1901 S.D. Sess. Laws 6, §§ 1-2 (prohibiting the use, manufacture, and selling of “any air gun or any article of fire works known as cannon fire crackers …, and all fire crackers more than three inches in length or … made wholly or in part of dynamite or giant powder”) [HeinOnline]
32. Utah: 1901 Utah Laws 97-98, ch. 96, §§ 1-3 (prohibiting the construction or mailing of “infernal machine[s]” defined as “any box, package, contrivance or apparatus, containing or arranged with an explosive or acid or poisonous or inflammable substance, chemical, or compound, or knife, or loaded pistol or gun or other dangerous or harmful weapon or thing constructed, contrived or arranged so as to explode, ignite or throw forth its contents, or to strike with any of its parts … under conditions, or in a manner calculated to endanger health, life, limb or property”) [HeinOnline]
33. South Carolina: 1903 S.C. Acts 127-28 (prohibiting the carry, manufacture, or sale of any pistols “less than twenty inches long and three pounds in weight”) [HeinOnline]
34. Alabama: 1907 Ala. Laws 80 (prohibiting the sale of “any pistol of less than twenty-four inches in length of barrel or any brass knucks, metalic knucks, dirks, slungshot, bowie knives or knife of like kind”) [HeinOnline]
35. Newman, Illinois: W.W. Pepper, et. Al. Revised Ordinances of the City of Newman, Illinois (1908) (prohibiting the sale of possession of any “slung shot or metallic knuckles,or other deadly weapon.”) [Making of Modern Law]
36. Maine: 1909 Me. Laws 141 (prohibiting possession of “any gun, pistol or other firearm, fitted or contrived with any device for deadening the sound of explosion” or “silencer”) [HeinOnline]
37. North Dakota: 1909 N.D. Laws 130–131, An Act Prohibiting the Use, Sale or Purchase of Any Device Known as a Silencer to Be Used on Any Firearm, ch. 122, §§ 1–4. (“No person shall be permitted to sell or offer for sale any device or attachment to any firearm which will silence or deaden the sound or natural report of the same when discharged.”) [HeinOnline]
38. Washington: 1909 Wash. Sess. Laws 973, § 266 (prohibiting the setting of “so-called trap, spring pistol, rifle, or other deadly weapon”) [HeinOnline]
39. New York: 1911 N.Y. Laws 442-43, § 1 (prohibiting the carry, possession, manufacture, or sale of blackjacks, slung-shots, billy clubs, sandclubs, sandbags, metal knuckles and bludgeons and prohibiting the possession “in any city, village or town of this state, any pistol, revolver or other firearm of a size which may be concealed upon the person, without a written license”) [HeinOnline]
40. Ohio: 1911 Ohio Sess. Laws 124 (prohibiting the manufacture or sale of brass knuckles, billies, slung-shots, sandbags, or blackjacks) [HeinOnline]
41. New Jersey: 1912 N.J. Sess. Laws 365-66, §§ 2-3 (prohibiting the possession, carry, use, manufacture, or sale of blackjacks, slung-shots, billies, sand-clubs, sandbags, bludgeons, and metal knuckles) [HeinOnline]
42. Vermont: 1912 Vt. Acts & Resolves 310 (prohibiting the use of “an appliance known as or used for a gunsilencer”) [HeinOnline]
43. Vermont: 1912 Vt. Acts and Resolves 261 “. . . and provided further that a person violating the prohibition against setting a spring gun or other device the object of which is to discharge a firearm shall be fined not more than five hundred dollars nor less than fifty dollars, and shall also be liable for twice the amount of the damage caused by his act to be recovered by the person sustaining the injury or loss, in an action on this”
44. Wisconsin: 1921 Wis. Sess. Laws 870, An Act . . . Relating to Wild Animals,ch. 530, § “(29.22 (1) No person shall hunt game with any means other than the use of a gun held at arm’s length and discharged from the shoulder; or place, spread or set any net, pitfall, spring gun, pivot gun, swivel gun, or other similar contrivance for the purpose of catching, or which might catch, take or ensnare game . . . and no person shall carry with him in any automobile any gun or rifle unless the same is unloaded, and knocked down or unloaded and inclosed within a carrying case[.]”
45. Iowa: 1913 Iowa Acts 307, ch. 297, § 2 (“It shall be unlawful to sell, to keep for sale or offer for sale, loan or give away, dirk, dagger, stiletto, metallic knuckles, sand bag or skull cracker.”) [HeinOnline]
46. Michigan: 1913 Mich. Pub. Acts 472, An Act Providing for the Registration of the Purchasers of Guns, Pistols, Other Fire-arms and Silencers for Fire-arms and Providing a Penalty for Violation, § 1-2 (requiring dealers of silencers to “keep a register in which shall be entered the name, age, occupation and residence . . . together with the number or other mark of identification, if any, on such . . . silencer for firearms.”) [HeinOnline]
47. Minnesota: 1913 Minn. Laws 55 (prohibiting “any silencer for a shotgun, revolver, rifle or other fire-arm”) [HeinOnline]
48. New Jersey: 1913 N.J. Laws 339, ch. 186, §§ 1-2 (prohibiting the use, manufacture, selling, or possession of “any air gun, spring gun, or pistol, or other weapon of a similar nature in which the propelling force is a spring or air and ejecting a bullet or missile smaller than three eighths of an inch in diameter, with sufficient force to injure the person”) [HeinOnline]
49. New Hampshire: 1915 New Hampshire Acts 180 (“No person shall set or use at any time any device the object of which is to discharge a firearm for the purpose of taking fur-bearing or other animals”) [HeinOnline]
50. North Dakota: 1915 N.D. Laws 96, ch. 83, §§ 1-2 (prohibiting the possession and carry of any “black-jack, slung-shot, billy, sand club, sand bag, bludgeon, metal knuckles, or any sharp or dangerous weapon” and “any gun, revolver, pistol or other dangerous fire arm loaded or unloaded … or any other dangerous or violent explosive”) [HeinOnline]
51. Vermont: 1915 Vt. Sess. Laws 344 (prohibiting the use, possession, manufacture, or sale of slung shots, blackjacks, or brass knuckles) [HeinOnline]
52. New York: 1916 N.Y. Laws 338-39, ch. 137, § 1 (prohibiting the sale or concealed carry of “any instrument, attachment, weapon or appliance for causing the firing of any gun, revolver, pistol, or other firearms to be silent or intended to lessen or muffle the noise of the firing”) [HeinOnline]
53. California: 1917 Cal. Stat. 221, §§ 1-3 (prohibiting slungshots, billy clubs, sandclubs, sandbags, bludgeons, metal knuckles, dirks, and daggers and further prohibiting the concealed carry of “any pistol, revolver, or other firearm” absent lawful permit) [HeinOnline]
54. Minnesota: 1917 Minn. Laws 354 (prohibiting the manufacture and concealed carry or possession of any “slung-shot, sand-club, or metal knuckles” and the concealed carry or possession of  “any dagger, dirk, knife, pistol, or other dangerous weapon”) [HeinOnline]
55. California: 1923 Cal. Sess. Laws 696 (punishing anyone who “manufactures or causes to be manufactured, or who imports into the state, or who keeps for sale, or offers or exposes for sale, or who gives, lends, or possesses any instrument or weapon of the kind commonly known as a blackjack. . . billy, sandclub, sandbag,” “slung-shot,” or “metal knuckles”) [HeinOnline]
56. Oregon: 1925 Oregon Acts 42, (“Section 1. It shall be unlawful for any person to place or set any loaded spring-gun or set-gun, or any gun or firearm or other device of any kind designed for containing or firing explosives in any place whatsoever where the same may be fired, exploded or discharged by the contact of any person or animal with any string, wire, rod, stick, spring or other contrivance affixed thereto or connected therewith or with the trigger thereof.”) [HeinOnline]
57. Massachusetts: 1926 Mass. Acts 256, ch. 261 (prohibiting “any instrument, attachment, weapon or appliance” that silences “the firing of any gun, revolver, pistol or other firearm”) [HeinOnline]
58. Massachusetts: 1927 Mass. Acts 413-16, ch. 326, §§ 1-5 (creating prohibitive licensing for the sale, purchase, and carrying of firearms and prohibiting the carry of “any stiletto, dagger, dirk knife, slung shot, metallic knuckles or sawed off shotgun”) [HeinOnline]
59. Michigan: 1927 Mich. Pub. Acts 888-89, § 3 (prohibiting the manufacture, sale, or possession of “any machine gun or firearm which can be fired more than sixteen times without reloading, or any muffler, silencer or device for deadening or muffling the sound of a discharged firearm, or any bomb or bombshell, or any blackjack, slung shot, billy, metallic knuckles, sandclub, sandbag or bludgeon”) [HeinOnline]
60. Rhode Island: 1927 R.I. Pub. Laws 256-59 (creating prohibitive licensing for the carry and possession of certain firearms and prohibiting the possession or carry of bombs or bomb shells “except for blasting or other commercial use” or for police or military purposes)[HeinOnline]
61. Rhode Island: 1927 R.I. Pub. Laws 259, § 8 (“It shall be unlawful within this state to manufacture, sell, purchase or possess except for military or police purposes, any muffler, silencer or device for deadening or muffling the sound of a firearm when discharged.”) [HeinOnline] 
62. Michigan: 1929 Mich. Pub. Acts 529, § 3 (prohibiting the manufacture, sale, or possession of “any gas ejecting device, weapon, cartridge, container, or contrivance designed or equipped for or capable of ejecting any gas which will either temporarily or permanently disable, incapacitate, injure or harm any person with whom it comes in contact”) [HeinOnline]
63. Michigan: Firearms, ch. 37, §§ 222–39, 1931 Mich. Pub. Acts 669, 669–71 (Franklin DeKleine Co.). Sec. 236. Setting spring guns, etc.—Any person who shall set any spring or other gun, or any trap or device operating by the firing or explosion of gunpowder or any other explosive, and shall leave or permit the same to be left, except in the immediate presence of some competent person, shall be guilty of a misdemeanor, punishable by imprisonment in the county jail not more than one year, or by a fine of not more than five hundred dollars, and the killing of any person by the firing of a gun or device so set shall be manslaughter.
64. New York: 1931 N.Y. Sess. Laws 1033 (punishing a persons “who carries or possesses any instrument or weapon of the kind commonly known as a black-jack, slungshot, billy, sand-club, sandbag, metal knuckles [or] bludgeon”) [HeinOnline]
65. South Carolina: 1931 S.C. Acts 78, An Act Declaring it unlawful for any person, firm, or corporation to place a loaded trap gun, spring gun, or any like devise in any building, or in any place, and providing punishment for the violation thereof: § 1. (“§ 1. Be it enacted by the General Assembly of the State of South Carolina: That it shall be unlawful for any person, firm, or corporation to construct, set, or place a loaded trap gun, spring gun, or any like device in any manner in any building, or in any place within this State, and any violation to the provisions of this Act shall be deemed a misdemeanor and punished by fine of not less than One Hundred ($100.00) Dollars and not more than Five Hundred ($500.00) Dollars, or by imprisonment of not less than thirty (30) days nor more than one (1) year, or by both fine and imprisonment, in the discretion of the Court.”)
66. District of Columbia: H.R. 8754, 72d Cong. §§ 1, 14 (1932) (making it a crime in D.C. to “possess any … metal knuckles,” “blackjack, sand club, sandbag,”(with some exceptions for black jacks)), “or “sawed-off shotgun” to include “any shotgun with a barrel less than twenty inches in length”) [HeinOnline]
67. District of Columbia: 47 Stat. 650 (1932) (“No person shall within the District of Columbia possess any . . . any instrument, attachment, or appliance for causing the firing of any firearm to be silent or intended to lessen or muffle the noise of the firing of any firearms”(with some exceptions for black jacks)) [HeinOnline]
68. California: 1933 Cal. Stat. 925, ch. 337, § 1 (prohibiting the possession or transportation of “any form of shell, cartridge, or bomb containing or capable of emitting tear gas, or any weapon designed for the use of such shell, cartridge or bomb”) [HeinOnline]
69. Hawaii: 1933 Haw. Sess. Laws 36, An Act Regulating the Sale, Transfer, and Possession of Firearms and Ammunition, § 7 (“The manufacture, possession, sale, barter, trade, gift, transfer, or acquisition of any . . . mufflers, silencers or devices for deadening or muffling the sound of discharged firearms. . .”) [HeinOnline]
70. National Firearms Act of 1934: 48 Stat. 1236-1240, 26 U.S.C.A. § 1132 et seq. (imposing registration requirements and restrictions on the possession, sale, and transportation of firearms, including shotguns and rifles having barrels less than 18 inches in length, certain firearms described as “any other weapons,” machine guns, and firearm mufflers and silencers) [HeinOnline]
71. New York: 1954 NY Sess. Laws 812 (punishing anyone “who offers, sells, loans, leases, or gives to any person” a switchblade and “any person who shall have, carry, or have in his possession” a switchblade) [HeinOnline]
72. Delaware: 1955 Del. Sess. Laws 993 (prohibiting “any person, firm or corporation to sell, offer for sale, or have in his or its possession any” switchblade.”) [HeinOnline]
73. Indiana: 1957 Ind. Sess. Laws 392 (“Making it unlawful “for any person, firm, or corporation to manufacture, or cause to be manufactured, possess, display, offer, sell, lend, give away, or purchase any” switchblade) [HeinOnline]
74. Maryland: 1957 Md. Sess. Laws 899 (“It shall be unlawful for any person, firm or corporation or the agent of either, whether a licensed dealer or not, to sell, barter, display or offer to sell or barter” a switchblade) [HeinOnline]
75. Illinois: 1957 Ill. Sess. Laws 78 (“It is unlawful for any person to carry or possess or sell, loan or give to any person, any black-jack, sling-shot, sand-club, sand-bag, metal knuckles, bludgeon” or switchblade) [HeinOnline]
76. Minnesota: 1959 Minn. Sess. Laws 233 (prohibiting the possession of switchblades)
    [HeinOnline]
77. Hawaii: 1959 Haw. Sess. Laws 168 (“Whoever knowingly manufactures, sells, transfers, possesses or transports in the Territory of Hawaii any switchblade knife.”) [ HeinOnline ] Vermont : 1959 Ver. Acts 134 (punishing a “person who possesses, sells or offers for sale a . . . weapon commonly known as a switchblade knife”) [HeinOnline]
78. Federal: 72 Stat 562, Pub. L. 85-623, An Act to Prohibit the Introduction or Manufacture for Introduction Into Interstate Commerce of Switchblades, Knives and for Other Purposes (punishing anyone who “knowingly introduces, or manufactures for introduction, into interstate commerce, or transports or distributes in interstate commerce, any switchblade knife.”) [HeinOnline]
79. Vermont: 1959 Ver. Sess. Laws 134, No. 151 (punishing a “person who possesses, sells
    or offers for sale a weapon commonly known as a ‘zip’ gun”) [HeinOnline]
80. Ohio: 1969 Ohio Laws 2027, 2028, § 2923.01 (“No person shall carry a pistol,
    REVOLVER. ZIP-GUN . . .”); [HeinOnline]
81. Ohio: 1971 Ohio Laws 1969, § 2923.17 (“No person shall knowingly acquire, have, carry, or use any dangerous ordinance.”); 1971 Ohio Law 1964, § 2923.11(J) (“(J) ‘Dangerous Ordinance’ means any of the following except as provided in division 9K) of this section: (1) Any Automatic or Sawed-off Firearms, or Zip-gun”). [HeinOnline]
82. New York, Binghamton: 1968 N.Y. Local Laws 37, Local Law No. 2 (Prohibition on selling, purchasing or carrying zip guns during a state of emergency in Binghampton, N.Y.) [HeinOnline]
83. New York, Scarsdale: 1968 N.Y. Local Law 3855, Local Law No. 2 (Same for Scarsdale, N.Y.) [HeinOnline]
84. California: 1988 Cal. Sess. Laws 1930, ch. 512, § 1 (“(a) Any person in this state who manufactures or causes to be manufactured, imports into the state, keeps for sale, or offers or exposes for sale, or who gives, lends, or possesses . . . any zip gun . . .”) [HeinOnline]
85. Texas: 1991 Tex. Laws 909, § 229 (“§ 1. (16) “Zipgun” means a device or combination of devices that was not originally a firearm and is adapted to expel a projectile through a smooth-bore or rifled-bore barrel by using the energy generated by an explosion or burning substance. § 2. a) A person commits an offense if he intentionally or knowingly possesses, manufactures, transports, repairs, or sells: . . . (9) a zip gun.”) [HeinOnline]

Gun Proving and Gunpowder Proving Laws

1. Rhode Island: 1776 R.I. Laws 18-19 (Oct. Sess.) (Requiring gunpowder be inspected and marked with the quality and punishing those who sell uninspected gunpowder with a fine of six pounds) [Source]
2. New Jersey: 1776-77 N.J. Laws 6-7, ch. 6, § 1 (requiring gunpowder be inspected, marked with quality and a certification of inspection) [Source]
3. Pennsylvania: 1795 Pa. Laws 240, § 2 (requiring gunpowder be inspected and graded using a “pendulum powder proof”) [Source]
4. Massachusetts: 1805 Mass. Laws 259 (allowing the governor to appoint officials to
   “prove all musket barrels and pistol barrels” and describing the method of proving. Upon successful proof the prover would apply a stamp “deeply impressed on said barrel, as that the same cannot be erased or disfigured”) [HeinOnline]
5. Massachusetts: 1809 Mass. Laws 444, ch. 52 (appointing gunpowder inspectors to
   “inspect, examine and prove all gun-powder) [HeinOnline]
6. Massachusetts: 1814 Mass. Acts 464-65, § 2.(” all musket barrels and pistol barrels, manufactured within this Commonwealth … be proved by the person appointed … with a charge of powder equal in weight to the ball which fits the bore of the barrel to be proved” and punishing those who “shall manufacture… or shall sell and deliver, or shall knowingly purchase any musket or pistol, without having the barrels first proved” with a $10 fine.) [Source]
7. New Hampshire: 1820 N.H. Laws 274, ch. 15 §§ 1-9 (“ it shall be the duty of each of said inspectors to inspect, examine and prove all gunpowder”) [Source]
8. Maine: 1821 Me. Laws 546, ch. 162 (authorizing governor to appoint officials to “ prove and try the strength of the barrels of all fire arms” and punishing those who “sell or offer for sale within this State, any new, or unused musket, rifle, or pistol barrel, without having the same first proved, marked, and certified according to the provisions of this Act” with a fine of $10 and anyone who “shall falsely alter the stamp or mark on the certificate of any prover of fire arms” with a fine of $100.) [Source]

Restrictions on Firing Capacity

1. California: 1927 Cal. Stat. 938, ch. 552, §§ 1-2 (prohibiting possession of “all firearms known as machine rifles, machine guns or submachine guns capable of discharging automatically and continuously loaded ammunition of any caliber in which the ammunition is fed to such gun from or by means of clips, disks, drums, belts or other separable mechanical device”) [HeinOnline]
2. New Jersey: 1927 N.J. Laws 180-81, ch. 95, §§ 1-2 (prohibiting any “machine gun or automatic rifle” defined to include “any weapon, mechanism or instrument not requiring that the trigger be pressed for each shot and having a reservoir, belt or other means of storing and carrying ammunition which can be loaded into the said weapon, mechanism or instrument and fired therefrom at a rate of five or more shots to the second”) [HeinOnline]
3. Rhode Island: 1927 R.I. Pub. Laws 256-57 (prohibiting the manufacture, sale, purchase, or possession of “any weapon which shoots more than twelve shots semi-automatically without reloading”) [HeinOnline]
4. Michigan: 1927 Mich. Pub. Acts 888-89, no. 372, § 3 (prohibiting the manufacture, selling, and possession of “any machine gun or firearm which can be fired more than sixteen times without reloading”) [HeinOnline]
5. Model Law: Report of Firearms Committee, Handbook of the National Conference on Uniform State Laws and Proceedings of the Thirty-Eighth Annual Meeting 422, 428 (1928) (prohibiting possession of any “any firearm which shoots more than twelve shots semi-automatically without reloading”) [HeinOnline]
6. Illinois: 1931 Ill. Laws 452-53, §§ 1-2 (prohibiting the possession, sale, manufacture, or transportation of “all firearms commonly known as machine rifles, machine guns and sub-machine guns of any caliber whatsoever, capable of automatically discharging more than eight cartridges successively without reloading, in which the ammunition is fed to such gun from or by means of clips, disks, belts, or other separable mechanical device”) [HeinOnline]
7. District of Columbia: H.R. 8754, 72d Cong. §§ 1, 14 (1932) (making it a crime in D.C. to possess “any firearm which shoots automatically or semiautomatically more than twelve shots without reloading”) [HeinOnline]
8. Louisiana: 1932 La. Acts 337-38, §§ 1-2 (prohibiting the purchase, sale, or possession of “all firearms … capable of automatically discharging more than eight cartridges successively without reloading, in which the ammunition is fed to such gun from or by means of clips, disks, belts, or other separable mechanical device”) [HeinOnline]
9. California: 1933 Cal. Stat. 1170, §§ 2-3 (prohibiting the sale or possession of “all firearms which are automatically fed after each discharge from or by means of clips, discs, drums, belts or other separable mechanical device having a capacity greater than ten cartridges”) [HeinOnline]
10. Minnesota: 1933 Minn. Laws 232-33, ​​ch. 190, §§ 1-3 (prohibiting possession, sale, or transport of “(a) [a]ny firearm capable of loading or firing automatically, the magazine of which is capable of holding more than twelve cartridges …(b) [a]ny firearm capable of automatically reloading after each shot is fired, whether firing singly by separate trigger pressure or firing continuously” if the firearm was modified to allow for a larger magazine capacity, and “(c) A twenty-two caliber light sporting rifle, capable of firing continuously by continuous trigger pressure”) [HeinOnline]
11. Ohio: 1933 Ohio Laws 189-90 (creating prohibitive licensing for “any firearm which shoots more than eighteen shots semi-automatically without reloading”) [HeinOnline]
12. South Dakota: 1933 S.D. Sess. Laws 245-47, ch. 206, §§ 1-8 (regulating the possession of any weapon “from which more than five shots or bullets may be rapidly or automatically, or semi-automatically discharged from a magazine”) [HeinOnline]
13. Texas: 1933 Tex. Gen. Laws 219, ch. 82, §§ 1-3 (prohibiting possession or use of any weapon “from which more than five (5) shots or bullets may be automatically discharged from a magazine by a single functioning of the firing device”) [HeinOnline]
14. Washington: 1933 Wash. Sess. Laws 335-36, ch. 64, §§ 1-2 (prohibiting any “weapon, mechanism, or instrument not requiring that the trigger be pressed for each shot and having a reservoir clip, disc, drum belt, or other separable mechanical device for storing, carrying, or supplying ammunition which can be loaded into such weapon, mechanism, or instrument, and fired therefrom at the rate of five or more shots per second”) [HeinOnline] 
15. South Carolina: 1934 S.C. Acts 1288 (prohibiting possession of “all firearms … capable of automatically discharging more than eight cartridges successively without reloading, in which the ammunition is fed to such gun from or by means of clips, disks, belts or other separable mechanical device”) [HeinOnline]
16. Virginia: 1934 Va. Acts 137-40 (regulating weapons “from which more than seven shots or bullets may be rapidly, or automatically, or semi-automatically discharged from a magazine,” as well as weapons “from which more than sixteen shots or bullets may be … discharged without reloading”) [HeinOnline]

Selected Academic Articles

1. Brian DeLay, The Myth of Continuity in American Gun Culture, 113 Cal. L. Rev. 1 (2025) (reviewing the history of repeating firearms and their regulation and concluding that “[p]ut into proper historical context, … assault weapons, high-capacity magazines, and ghost guns represented ‘dramatic technological changes’ that provoked ‘unprecedented societal concerns’”)
2. Deborah Azrael et al., A Critique of Findings on Gun Ownership, Use, and Imagined Use from the 2021 National Firearms Survey: Response to William English, 78 SMU L. Rev. (forthcoming 2025) (assessing, “as a sort of peer review,” William English’s “2021 National Firearms Survey,” which is often relied on by plaintiffs challenging laws restricting assault weapons and large-capacity magazines, and finding that “several of his findings are based on flawed evidence” and, “[i]n addition, several findings are difficult to interpret, and do not support the lessons litigants have drawn”)
   • For additional critiques of English’s survey, see Mike McIntire & Jodi Kantor, The Gun Lobby’s Hidden Hand in the 2nd Amendment Battle, N.Y. Times (June 18, 2024), and Will Van Sant, The Secret Plan to Strike Down U.S. Gun Laws, The Trace (Jan. 15, 2025)
3. Mark Anthony Frassetto, Mass Violence and the Second Amendment: Analogizing Historical Prohibitions on Armed Groups to Modern Prohibitions on Assault Weapons and Large-Capacity Magazines, 76 Ala. L. Rev. 43 (2024) (explaining that historical prohibitions on armed groups are a proper analogue for modern assault weapon and large-capacity magazine laws because they are all “aimed at the same principle: prohibiting the means of committing mass violence”)
4. Darrell A.H. Miller & Jennifer Tucker, Common Use, Lineage, and Lethality, 55 U.C. Davis. L. Rev. 2495 (2022) (proposing lethality, based on the Theoretical Lethality Index developed for the U.S. military, as a proper metric for assessing whether a weapon is a constitutionally protected “arm”)
5. Robert J. Spitzer, Understanding Gun Law History After Bruen: Moving Forward by Looking Back, 51 Fordham Urb. L. J. 57 (2023) (discussing the emergence and regulatory history of assault weapons and large-capacity magazines, and explaining that “[c]urrent restrictions on assault weapons and detachable ammunition magazines are part of a pattern in America’s history of legislative restrictions on particular weapons stretching back centuries”)
   • For additional work by Professor Spitzer on this topic, see Robert J. Spitzer, Gun Accessories and the Second Amendment: Assault Weapons, Magazines, and Silencers, 83 Law & Contemp. Probs. 231 (2020); see also Robert J. Spitzer, Gun Law History in the United States and Second Amendment Rights, 80 Law & Contemp. Probs. 55 (2017) (discussing historical laws restricting “dangerous or unusual weapons” and explaining that “new laws were enacted not when these weapons were invented, but when they began to circulate widely in society”)

Social Science

Use of Assault Weapons and LCMs in Mass Shootings and Crime

1. Everytown for Gun Safety Support Fund, Mass Shootings in America (Jun. 2, 2021)
   • The five deadliest mass shootings incidents in the US all involved the use of assault weapons and/or LCMs. 
   • From 2009 to 2020, mass shootings that involved an assault weapon resulted in (i) six times the number of people shot compared to mass shootings where there was no assault weapon; (ii) 21.8 times as many people injured; and (iii) 2.4 times as many deaths. Of the 76 mass shootings where magazine size was known, those that involved the use of LCMs led to (i) five times the number of people shot compared to mass shootings that did not involve LCMs; (ii) 15 times as many people injured; and (iii) twice as many deaths. 
2. Bonnie Berkowitz et al., The Terrible Numbers That Grow With Each Mass Shooting, Wash. Post (May 9, 2021) (compiling data on the 189 public shootings in which four or more people were killed, including the type of weapon used) 
3. Violence Policy Center, Mass Shootings in the United States Involving Large Capacity Ammunition Magazines (2022) (compiling mass shootings involving LCMs from 1980 to 2022) 
4. Christopher S. Koper, Assessing the Potential to Reduce Deaths and Injuries from Mass Shootings Through Restrictions on Assault Weapons and Other High-Capacity Semiautomatic Firearms, 19 Criminology & Pub. Pol’y 147 (2020)
   • Assault weapons and other large-capacity semiautomatic weapons are used in between 20% and 58% of all firearm mass murders, and in a particularly high share of public mass shootings. Average fatalities are 38% to 85% higher, and total victims killed or wounded are two to three times higher, when LCMs are used.
   • The study estimated that LCM restrictions could potentially reduce total fatalities by 11% to 15%, and total injuries by 24% to 26% across all firearm mass-murder incidents. Focusing particularly on public mass shootings, it projected that total deaths and injuries could potentially decline in these cases by somewhere between one-third and one-half.
5. Charles DiMaggio et al., Changes in U.S. Mass Shooting Deaths Associated with the 1994-2004 Federal Assault Weapons Ban: Analysis of Open-Source Data, 86 J. of Trauma and Acute Care Surgery 11 (2019) 
   • A study of mass shooting incidents between 1981 to 2017 revealed that “[i]ncidents in which weapons were characterized as assault rifles accounted for 430 or 85.8% of mass-shooting fatalities.” 
6. Christopher S. Koper et al., Criminal Use of Assault Weapons and High-Capacity Semiautomatic Firearms: An Updated Examination of Local and National Sources, 95 J. Urban Health 313 (2018)
   • Assault weapons alone account for up to 12% of guns used in all crime and up to 16% of guns used in murders of police. Assault weapons and other semiautomatic weapons with LCMs appear to account for 22 to 36% of crime guns in most places, with some estimates upwards of 40% for cases involving serious violence. 

Severity of Physical Injuries from Assault Weapons

1. Scott Pelley, What Makes the AR-15 Style Rifle the Weapon of Choice for Mass Shooters, 60 Minutes (June 23, 2019) (comparing the physical damage caused by an AR-15 rifle versus a a 9mm handgun) 
2. Heather Sher, What I Saw Treating the Victims From Parkland Should Change the Debate on Guns, The Atlantic (Feb. 22, 2018) (explaining how injuries from AR-15s differ from injuries from handguns)
3. Gina Kolata & C.J. Shivers, Wounds From Military-Style Rifles? ‘A Ghastly Thing to See,’ N.Y. Times (Mar. 4, 2018) (compiling accounts from trauma surgeons who have treated wounds caused by military-style rifles) 
4. Tim Craig et al., As the Wounded Kept Coming, Hospitals Dealt with Injuries Rarely Seen in the U.S., Wash. Post (Oct. 3, 2017) (recounting the injuries from the Las Vegas shooting) 
5. Peter M. Rhee et al., Gunshot Wounds: A Review of Ballistics, Bullets, Weapons, and Myths, 80 J. Trauma & Acute Care Surgery 853 (2016) (explaining that assault weapons are capable of firing far more bullets at a faster rate than other firearms)
6. Sarah Zhang, What an AR-15 Can Do to the Human Body, Wired (June 17, 2016) (comparing the kinetic energy released by a bullet fired from an AR-15 versus a bullet fired from a 9mm handgun) 
7. Declaration of Christopher B. Colwell, M.D., in Support of Defendants’ Opposition to Motion for Preliminary Injunction, Miller v. Becerra, No. 19-CV-1537, at  ¶¶ 8, 12 (S.D. Cal. Jan. 9, 2020)
   • “Gunshot wounds from assault weapons, such as AR-15 platform rifles and Intratec TEC-9 pistols, tend to be higher in complexity with higher complication rates than such injuries from non-assault weapons, increasing the likelihood of morbidity in patients that present injuries from assault weapons. In my experience, assault weapons tend to cause far greater damage to the muscles, bones, soft tissues, and vital organs. They are too often shredded beyond repair. … It is my opinion that while all weapons pose risk, assault weapons, especially when equipped with large capacity magazines, pose a far greater risk to the public from a medical standpoint than non-assault weapons.” 
8. Jennifer Henderson, ‘There’s Nothing to Repair’: Emergency Docs on Injuries From Assault Weapons, Medpage Today (May 31, 2022) (describing the first-hand experiences of physicians who, in responding to the scenes of mass shootings, observed the extensive physical damage inflicted by the bullets of an assault weapon as compared to the injuries inflicted in other shootings involving non semi-automatic firearms)
9. Josh Campbell, See how AR-15 style guns create ‘explosion inside the body’, CNN (June 8, 2022)  

Impact of the Federal Prohibition on Assault Weapons and LCMs

1. Lori Post et al., Impact of Firearm Surveillance on Gun Control Policy: Regression Discontinuity Analysis, 7 JMIR Pub. Health & Surveillance (2021) 
   • “We estimate that the [Federal Assault Weapons Ban] prevented 11 public mass shootings during the decade the ban was in place. A continuation of the [law] would have prevented 30 public mass shootings that killed 339 people and injured an additional 1139 people.”
2. Louis Klarevas, Rampage Nation: Securing America from Mass Shootings 240-43 (2016)
   • As compared with the 10-year period before the federal law prohibiting assault weapons and LCMs went into effect, the number of gun massacres (where six or more people were shot and killed) fell by 37% during the 10-year period when the law was in effect, and the number of people dying from gun massacres fell by 43%. In the decade after the federal prohibition lapsed, gun massacres increased by 183% and massacre deaths increased by 239%. 
   • See Christopher Ingraham, It’s Time to Bring Back the Assault Weapons Ban, Gun Violence Experts Say, Wash. Post. (Feb. 14, 2018) (discussing Klarevas’s research) 
3. John Donohue & Theodora Boulouta, That Assault Weapon Ban? It Really Did Work, N.Y. Times (Sep. 4, 2019)
   • Compared to the 10-year period before the federal prohibition went into effect, this study found a 25% drop in public mass shootings in which at least six people were killed during the decade the prohibition was in effect, and a 40% drop in fatalities. The decade after the federal prohibition elapsed saw a 347% increase in fatalities in mass shootings, even as overall violent crime continued downward.
   • Graphs supporting these findings are available at John Donohue & Theodora Boulouta, The Assault Weapon Ban Saved Lives, Stanford Law School Blog (Oct. 15, 2019) (demonstrating that these findings also hold true even if the definition of mass shooting is adjusted to shootings in which at least four people are killed) 
4. Charles DiMaggio et al., Changes in U.S. Mass Shooting Deaths Associated with the 1994-2004 Federal Assault Weapons Ban: Analysis of Open-Source Data, 86 J. of Trauma and Acute Care Surgery 11 (2019) 
   • Mass shooting fatalities were 70% less likely to occur from 1994 to 2004, when the federal prohibition on assault weapons and LCMs was in effect, than during the other 26 years studied (13 years before and 13 years after this period), when the prohibition was not in effect. Researchers estimate that, had it been in effect, a federal prohibition on assault weapons and LCMs would have prevented 314 of 448 mass shooting deaths that occurred during the studied periods when the prohibition was not in effect (1981–1994 and 2004–2017). 

Impact of State Prohibitions on Assault Weapons and LCMs

1. Louis Klarevas et al., The Effect of Large-Capacity Magazine Bans on High-Fatality Mass Shootings, 1990–2017, 109 Am. J. Pub. Health 1754 (2019)
   • An analysis of 69 high-fatality mass shootings from 1990 to 2017 found that incidence of high-fatality mass shootings was more than double and annual number of deaths more than three times higher when comparing non-LCM ban states to LCM ban states, with similar results in multivariate analyses, and ultimately concluding that LCM bans appear to reduce both incidence of, and number of people killed in, high-fatality mass shootings.
2. Michael Siegel et al., The Relation Between State Gun Laws and the Incidence and Severity of Mass Public Shootings in the United States, 1976–2018, 44 Law & Human Behavior 147 (2020)
   • State LCM prohibitions were associated with 38% fewer fatalities and 77% fewer nonfatal injuries when a mass shooting occurred.  
3. Sam Petulla, Here is 1 Correlation Between State Gun Laws and Mass Shootings, CNN, (Oct. 5, 2017) (reporting on the findings of an original analysis conducted by Boston University Professor Michael Siegel) 
   • “Whether a state has a large capacity ammunition magazine ban is the single best predictor of the mass shooting rate in that state … These states are associated with a 63% lower rate of mass shootings[.]”
4. Declaration of Professor Louis Klarevas, Miller v. Becerra, No. 19-CV-1537, at ¶ 27 (S.D. Cal. Jan. 22, 2020) (ECF Dkt. No. 33-5)
   • From 1990-2019, states that restricted possession of certain assault weapons experienced a 46% decrease in the incidence rate and a 57% decrease in the fatality rate for all gun massacres, regardless of the weaponry used by the mass murderers. Additionally, states with assault weapons bans in place experienced 54% fewer gun massacres involving the use of assault weapons and 67% fewer deaths resulting from such attacks perpetrated with assault weapons.
5. Mark Gius, The Impact of State and Federal Assault Weapons Bans on Public Mass Shootings, 22 Applied Econ. Letters 281 (2015)
   • State-level assault weapons and LCM prohibitions have statistically significant and negative effects on deaths from public mass shootings, reducing such deaths by 45%.

Non-Physical Impacts of Mass Shootings

1. Maggie Koerth, Mass Shootings Can Traumatize People Who Weren’t Even There, FiveThirtyEight (June 9, 2022) (discussing the vicarious and community trauma caused by gun violence, according to University of Arizona Professor Jennifer Carlson)
2. Am. Psychological Ass’n, Stress in America 2020 (Oct. 2020)  
   • In 2020, 62% of U.S. adults stated that mass shootings were a significant source of stress for them.  
3. Am. Psychological Ass’n, Stress in America 2019 (Nov. 2019) 
   • In 2019, 71% of adults stated that mass shootings were a significant source of stress for them, making mass shootings the most prevalent source of stress cited by U.S. adults in 2019. 
4. Nikki Graf, A Majority of U.S. Teens Fear a Shooting Could Happen at Their School, and Most Parents Share Their Concern, Pew Research Center (Apr. 18, 2018)
   • 57% of teens in the United States reported that they were “very worried” or “somewhat worried” about the possibility of a shooting at their school, and the same was true for 63% of parents. 
5. Sarah R. Lowe & Sandro Galea, The Mental Health Consequences of Mass Shootings, 18 Trauma, Violence & Abuse 62 (2017)  
   • Mass shootings harm the mental health of both direct survivors and community members, including through post-traumatic stress and depression, and even those living far away, who can experience increased fear of crime or victimization and uncertainty about their safety at school and in the community. 
6. Marika Cabral et al., Trauma at School: The Impacts of Shootings on Students’ Human Capital and Economic Outcomes, Nat’l Bureau of Econ. Research (2021) 
   • “We find that shooting-exposed students have an increased absence rate and are more likely to be chronically absent and repeat a grade in the two years following the event. We also find adverse long-term impacts on the likelihood of high school graduation, college enrollment and graduation, as well as employment and earnings at ages 24–26.”
7. Maya Rossin-Slater et al., Local exposure to school shootings and youth antidepressant use, 117 PNAS 23484 (2020) (finding that local exposure to fatal school shootings leads to persistent and significant increases in youth antidepressant use)
8. Phillip Levine & Robin McKnight, Exposure to a School Shooting and Subsequent Well-Being, Nat’l Bureau of Econ. Research Working Paper Series (2020) (examining impact of school shootings on educational performance and long-term health consequences) 
   • The “strongest evidence comes in the form of lower test scores among students affected by the Sandy Hook school shooting and an increased risk of suicide or accidental deaths among students affected by the Columbine High School shooting.”

Defensive Gun Uses

1. Defendants’ Post-Trial Proposed Findings of Fact and Conclusions of Law, Miller v. Becerra, No. 19-CV-1537-BEN-JLB, at  ¶ 94 (S.D. Cal. Feb. 16, 2021) (ECF Dkt. No. 103) 
   • According to stories of defensive gun uses aggregated by the National Rifle Association, individuals fired an average of 2.1 rounds when firearms were used in self-defense in the home. A review of 4,841 news stories nationwide involving defensive gun use in the home revealed a similar number (2.34 rounds).