Are Automatic Knives Legal in Massachusetts?
The Short Answer
It's complicated — and it just got a lot more interesting.
Massachusetts has one of the oldest switchblade bans in the country, written into General Laws Chapter 269, Section 10(b). For decades, carrying an automatic knife with a blade over 1.5 inches was a felony. But in August 2024, the Massachusetts Supreme Judicial Court ruled in Commonwealth v. David E. Canjura that the ban on carrying a switchblade knife violates the Second Amendment right to bear arms.
That ruling didn't erase the statute from the books — the legislature hasn't repealed or amended Section 10(b) yet. But the highest court in the state has said the switchblade carry ban is unconstitutional. That changes the practical landscape significantly, even if the law itself still reads the same way it did in 1957.
If you own or carry automatic knives in Massachusetts, you need to understand both the statute as written and what the Canjura decision means for enforcement.
What Massachusetts Law Actually Says
The Statute (M.G.L. Chapter 269, Section 10(b))
The relevant language reads:
"Whoever, except as provided by law, carries on his person, or carries on his person or under his control in a vehicle, any stiletto, dagger or a device or case which enables a knife with a locking blade to be drawn at a locked position, any ballistic knife, or any knife with a detachable blade capable of being propelled by any mechanism, dirk knife, any knife having a double-edged blade, or a switch knife, or any knife having an automatic spring release device by which the blade is released from the handle, having a blade of over one and one-half inches..."
The penalty: imprisonment for not less than 2.5 years nor more than 5 years in state prison, or 6 months to 2.5 years in county jail. For first offenders without a prior felony conviction, the court may reduce this to a fine of up to $50 or up to 2.5 years in jail.
What That Means in Plain English
Before Canjura, Massachusetts law prohibited carrying on your person or in your vehicle:
- Switch knives (switchblades) with blades over 1.5 inches
- Any knife with an automatic spring release with blades over 1.5 inches
- Stilettos, daggers, and dirk knives (no blade length threshold — any size)
- Double-edged knives (no blade length threshold)
- Ballistic knives (completely prohibited)
The 1.5-inch blade limit applied specifically to automatic/switch knives. Stilettos, daggers, and double-edged blades were banned at any length.
The Canjura Decision (August 2024)
In Commonwealth v. Canjura, the Supreme Judicial Court — the highest court in Massachusetts — held that a ban on carrying a switchblade knife violates the right to bear arms under the Second Amendment. The court applied the framework established by the U.S. Supreme Court in New York State Rifle & Pistol Association v. Bruen (2022), finding that switchblades are "arms" protected by the Second Amendment and that Massachusetts could not demonstrate a historical tradition of banning such weapons.
The statute has not been amended by the legislature. It still reads the same. But the state's highest court has declared the switchblade carry provision unconstitutional, and prosecutors statewide are now aware of that ruling.
OTF Knives in Massachusetts
OTF (out-the-front) knives are automatic knives. Under the statute as written, they fall under "any knife having an automatic spring release device by which the blade is released from the handle." Before Canjura, an OTF with a blade over 1.5 inches was illegal to carry.
Post-Canjura, the constitutional analysis applies to OTFs just as it does to side-opening automatics. However, a double-edged OTF also falls under the separate prohibition on "any knife having a double-edged blade" — and the Canjura ruling specifically addressed switchblades. Whether the court would extend the same reasoning to double-edged blades hasn't been tested yet.
Bottom line: Single-edge OTF knives are in the strongest legal position post-Canjura. Double-edged OTFs carry additional risk because they trigger a separate prohibition that hasn't been directly challenged.
Switchblades vs. Automatic Knives: What Massachusetts Considers Them
Massachusetts law uses the terms "switch knife" and "any knife having an automatic spring release device by which the blade is released from the handle." These cover:
- Side-opening automatic knives (traditional switchblades)
- OTF automatic knives (out-the-front deployment)
- Any spring-loaded mechanism that deploys the blade from the handle
The statute does not distinguish between OTFs, side-openers, or button-lock automatics. If the blade deploys by spring or mechanical action, it's an automatic knife under Massachusetts law.
Assisted openers — knives that require manual force to begin opening, with a spring that only assists after the blade is partially deployed — are generally not considered automatic knives under this statute. They remain legal to carry.
Carrying an Automatic Knife in Massachusetts
Open Carry
Massachusetts does not have a separate open carry framework for knives. Section 10(b) applies to carrying "on his person" — it does not distinguish between open and concealed. Prior to Canjura, carrying an automatic knife with a blade over 1.5 inches was prohibited regardless of how you carried it.
Concealed Carry
Same analysis. The statute doesn't draw an open/concealed line for knives. The prohibition (now constitutionally challenged) was on carrying, period.
Post-Canjura Reality
Following the Canjura ruling, carrying an automatic knife should be constitutionally protected. However, since the legislature has not amended the statute, the practical advice is: carry with awareness. Law enforcement officers may not all be current on the ruling, and an arrest followed by dismissal is still an arrest.
Where You Can't Carry (Restricted Locations)
Regardless of Canjura, Massachusetts restricts weapons — including knives — in certain locations:
- Schools (elementary, secondary, college, university) — M.G.L. Ch. 269, § 10(j)
- Government buildings — courthouses, state buildings, election sites — M.G.L. Ch. 269, § 10(k)
- Airports — federal law applies
The school zone prohibition carries a fine of up to $1,000 or imprisonment up to 2 years, or both.
Blade Length Restrictions
The statute sets a 1.5-inch blade limit for automatic/switch knives specifically. Below 1.5 inches, the automatic knife provision doesn't apply (though other provisions for stilettos, daggers, and double-edged blades have no blade length threshold).
Post-Canjura, the enforceability of this 1.5-inch limit for automatics is questionable, but it remains on the books.
What About Assisted Openers?
Assisted-opening knives — where you manually start the blade opening and a spring helps finish the motion — are not automatic knives under Massachusetts law. They are legal to own and carry. The federal Switchblade Knife Act was also amended in 2009 to explicitly exclude assisted openers.
Buying Automatic Knives in Massachusetts
You can purchase automatic knives online and have them shipped to Massachusetts. The Canjura decision strengthens the legal basis for ownership and possession. Retailers — including us — ship to Massachusetts, but you are responsible for understanding the current state of the law, including any local ordinances that may apply.
Massachusetts does not have state preemption for knife laws. Cities and towns can enact their own restrictions that may be more restrictive than state law. Boston, Cambridge, and other municipalities may have additional regulations. Check local ordinances before carrying.
Age Restrictions
Section 10(b) applies to all persons. Massachusetts does not set a specific minimum age for knife possession in the general statute, but minors (under 18) face additional restrictions under juvenile law, and selling certain weapons to minors may violate separate statutes.
Recent Changes
- August 2024: Commonwealth v. Canjura — SJC rules switchblade carry ban unconstitutional under the Second Amendment
- The legislature has not yet amended Chapter 269, Section 10(b) to reflect the ruling
- No new knife-specific legislation has passed as of early 2026
Frequently Asked Questions
Can I carry an OTF knife in Massachusetts?
Post-Canjura, a single-edge OTF knife is in strong legal territory. The court struck down the switchblade carry ban as unconstitutional. Double-edged OTFs carry more risk due to the separate double-edged blade prohibition.
Are switchblades illegal in Massachusetts?
The statute still says yes, but the state's highest court says the carry ban is unconstitutional. Ownership at home has generally been tolerated even before Canjura. The law is in transition — carry with awareness.
Is there a blade length limit for automatic knives in Massachusetts?
The statute sets 1.5 inches for automatics specifically, but the constitutional validity of that limit is now in question after Canjura. No blade length limit exists for non-automatic knives in the general carry statute.
Legal Disclaimer
This article is for informational purposes only and does not constitute legal advice. Knife laws change — sometimes faster than websites update. Federal, state, and local laws may all apply to your situation, and local ordinances can be more restrictive than state law.
Massachusetts is in a particularly dynamic period for knife law following the Canjura decision. The statute still reads one way; the court has ruled another. Before purchasing, carrying, or traveling with any automatic knife, OTF knife, or switchblade, verify current laws with official state and local sources. We are not attorneys, and we are not responsible for actions taken based on this information.
When in doubt, consult a licensed attorney in your jurisdiction.