Automatic knives are legal to own and carry in Massachusetts. In 2024, the Massachusetts Supreme Judicial Court struck down the state’s decades-old ban on switchblades, ruling it violated the Second Amendment. You can now carry one openly or concealed, with no blade-length cap, no permit, and no age threshold under state law. School zones, local ordinances, and federal shipping rules are the exceptions worth knowing about.
What Changed in 2024
For decades, Massachusetts General Laws Chapter 269, Section 10(b) made it a crime to carry a switchblade or any knife with an automatic spring-release mechanism and a blade longer than one and a half inches.1General Court of Massachusetts. Massachusetts General Laws Chapter 269 Section 10 A conviction carried two and a half to five years in state prison, or six months to two and a half years in jail.
In Commonwealth v. Canjura, the Supreme Judicial Court held that prohibition unconstitutional.2Justia Law. Commonwealth v. Canjura Applying the framework from New York State Rifle & Pistol Association v. Bruen, which requires weapons restrictions to be consistent with the nation’s historical tradition of arms regulation, the court found Massachusetts could not meet that standard for switchblades. The defendant’s conviction was reversed.3Mass.gov. Massachusetts Law About Weapons (Non-Firearms)
The switchblade language still appears in the text of Section 10(b) because the statute hasn’t been formally amended, but that portion is unenforceable. Carrying an automatic knife on your person or in a vehicle is no longer a crime under state law. Massachusetts does not distinguish between concealed and open carry for knives, so how you carry the knife doesn’t change anything.4Mass.gov. Massachusetts General Laws c.269 Section 10 – Carrying Dangerous Weapons
School Zones Are Still Off-Limits
Section 10(j) makes it a crime to possess any “dangerous weapon” in an elementary school, secondary school, college, or university, including the grounds and school transportation, without written authorization from the school board or officer in charge.5General Court of Massachusetts. Massachusetts General Laws Chapter 269 Section 10 An automatic knife can qualify. Canjura did not touch this provision.
The penalty is a fine of up to $1,000, up to two years in jail, or both. The only exemptions are qualified law enforcement officers and qualified retired law enforcement officers under the federal Law Enforcement Officers Safety Act, and certified Massachusetts law enforcement officers under Chapter 6E.5General Court of Massachusetts. Massachusetts General Laws Chapter 269 Section 10
Check Your City or Town
Massachusetts has no statewide knife preemption law. Cities and towns can pass their own ordinances restricting knives, and those local rules can be stricter than state law. Before you carry an automatic knife in a particular municipality, check whether a local ordinance applies. Legal under state law doesn’t always mean legal on your block.
Buying One and Having It Shipped
The Federal Switchblade Act, 15 U.S.C. §§ 1241–1244, restricts the shipment and sale of automatic knives across state lines. Knowingly shipping, transporting, or distributing a switchblade in interstate commerce carries penalties of up to $2,000, up to five years in prison, or both.6GovInfo. U.S. Code Title 15 Chapter 29 – Manufacture, Transportation, or Distribution of Switchblade Knives The federal definition covers any knife with a blade that opens automatically by pressing a button or other handle device, or by gravity or inertia.
Common carriers moving knives in the ordinary course of business are not liable under the Act. In practice, many retailers ship automatic knives to states where possession is legal, and the federal statute is rarely enforced against individual buyers. The legal risk falls primarily on commercial sellers and distributors.6GovInfo. U.S. Code Title 15 Chapter 29 – Manufacture, Transportation, or Distribution of Switchblade Knives
Automatic vs. Assisted-Opening
If you’re shopping and see “assisted opening” or “spring-assisted,” that’s not the same category. An assisted-opening knife has a spring that helps the blade deploy, but you have to apply manual pressure to the blade itself to overcome the spring’s bias toward closure. An automatic knife deploys the blade entirely by pressing a button or switch on the handle, with no contact with the blade.
Assisted-opening knives were never covered by the Massachusetts switchblade ban, and the Federal Switchblade Act explicitly exempts them.6GovInfo. U.S. Code Title 15 Chapter 29 – Manufacture, Transportation, or Distribution of Switchblade Knives They face no special restrictions under either.
Other Knives Section 10(b) Still Prohibits
Canjura addressed switchblades specifically. Section 10(b) still prohibits carrying stilettos, daggers, dirk knives, double-edged knives, ballistic knives, and locking-blade knives contained in a device or case that allows the blade to be drawn in a locked position.1General Court of Massachusetts. Massachusetts General Laws Chapter 269 Section 10 Whether any of those bans might fall to a similar Bruen-based challenge is an open question, but until a court rules, they remain illegal to carry. Standard folding knives, fixed-blade hunting knives, and kitchen knives are not on the list.