Knife Laws in Colorado

Colorado falls into the broad middle ground of states which, legally speaking, are neither “knife-friendly” (similar to Alaska) nor “knife-restrictive” (in the manner of California). In Colorado, a few knife types, mostly those similar to switchblades or gravity knives, are completely illegal irrespective of their length. All other knives, whether they have fixed or folding blades, are legal, with the type of carry permitted by law (open or concealed) determined by the blade length.

Several gray areas exist in Colorado knife law, including the possession of a balisong knife (probably, but not certainly, illegal), and concealed carrying of hunting or fishing knives exceeding the 3.5” legal limit. Considered over time, Colorado’s knife laws have gradually relaxed, with the biggest change occurring in 1971 when concealed carry first became legal in the Centennial State.

Legality of Knife Possession

Colorado’s criminal code places knives into two categories, those which are legal to own and carry, and those which are illegal to own or carry. A folding pocket knife; fixed blade knives such as a KA-BAR knife, a Bowie knife, or a dagger; larger folding knives, including certain hunting knives; and even knives that are disguised to resemble other objects, such as belt buckle knives and lipstick knives. Within this category, the length of the blade determines whether the knife is suitable for concealed use, or open carry only.

It should be noted that disguised knives count as automatically concealed and therefore cannot exceed the legal blade size imposed for concealment. Since this is generally 3.5”, sword canes are probably (though not specifically) illegal in Colorado.

The legal status of balisong knives, also called butterfly knives, is uncertain in Colorado. Though it resembles a gravity knife in some particulars, no case involving this a balisong knife has yet appeared in the Colorado court system, and consequently no precedent exists to define the implement’s legality. Those people who choose to carry such a knife must realize that they are doing so at their own risk and might be imprisoned for doing so.

Certain other weapon-type knives, however, such as push knives, can be carried concealed legally provided that their blade is under 3.5” in length. The case of A.P.E. v People in 2001, in which the petitioner’s name was publicly redacted due to their being a minor 14 years old at the time, noted that prior to 1971 Colorado law forbade concealed weapons entirely. Since the law was amended specifically to allow concealed weapons under 3.5”, the court decided such a knife could be considered a collectible, decorative object, or hunting or fishing tool even if it resembled a combat knife, and therefore ruled in A.P.E.’s favor.

Ballistic knives, gravity knives, and switchblade knives are illegal not only to carry in public, but to possess. In the Colorado Revised States, Title 18, Chapter 12, Section 102 – C.R.S. 18-12-102 (2014) – classifies these knives as illegal weapons alongside machine guns, sawed-off shotguns, blackjacks, and firearms with silencers. Knives with similar properties, specifically the ability to deploy the blade instantly or nearly so one-handed by using centrifugal force or a mechanical trigger, naturally fall under the same classification.

Not all illegal knives are created equal according to Colorado law. Switchblades and gravity knives are classified specifically as “illegal weapons,” whose possession subjects the owner to prosecution for a Class 1 Misdemeanor. Ballistic knives bear the descriptor “dangerous weapons,” making their possession a Class 5 Felony for the first violation and a Class 4 Felony for subsequent violations.

Note that since metal knuckles (brass knuckles) are classed as illegal weapons, an otherwise legal knife type which includes metal finger rings is made illegal by them, since they can be used as brass knuckles.

Knife Length Limit

The state of Colorado places no legal limit on the length of an openly carried knife’s blade. A hunting knife, a Bowie knife, or even, theoretically, a sword or machete could be openly carried legally. A hard limit of 3.5” blade length is imposed on concealed knives, however.

Concealed Carry of Knives

The state of Colorado itself imposes a 3.5” limit on concealed blades. One major exception to this rule is found in Colorado Revised Statutes 18-12-101(1)(f), 6 C.R.S. (2000). Section 1, subsection f of 18-12-201 allows concealed carrying of hunting or fishing knives longer than 3.5”, provided they are carried for sports. The owner must use this fact as an affirmative defense following arrest, however.

With no preemption clause in the legal codes, municipalities and counties are free to make their own ordinances regarding maximum length. Most adopt a 3.5” maximum length for concealed knives, while Silt, CO disallows knives with 3.5” or greater blades. Aspen and Boulder directly outlaw concealed carrying.

Other Knife Law Considerations in Colorado

Arizona is a “knife-neutral” state allowing reasonable freedom of choice to many knife owners. The state recognizes the validity of some unusual knife carrying decisions related to outdoor sports such as hunting and fishing, while the case of A.P.E. v People shows the courts are open to delivering a verdict favorable to knife owners when criminal intent seems doubtful or absent. Though many localities have their own knife rules and are under no obligation to accept state legal limits, most are in line with the state’s decisions, excepting a total concealed knife ban in a handful of major cities.

Resources and Further Reading$FILE/SenState0123AttachA.pdf