concealed is anything that is hidden or see below
A person commits a class 2 misdemeanor if such person knowingly and unlawfully:
(a) Carries a knife concealed on or about his or her person
Colorado - Criminal Code Section 18-12-101. Definitions...
(e) "Gravity knife" means any knife that has a blade
released from the handle or sheath thereof by the force of
gravity or the application of centrifugal force, that when
released is locked into place by means of a button,
spring, lever, or other device... (f) "Knife" means any
dagger, dirk, knife, or stiletto with a blade over 3-1/2
inches in length, or any other dangerous instrument
capable of inflicting cutting, stabbing, or tearing
wounds, but does not include a hunting or fishing knife
carried for sports use. The issue that a knife is a
hunting or fishing knife must be raised as an affirmative
defense. (j) "Switchblade knife" means any knife, the
blade of which opens automatically by hand pressure
applied to a button, spring, or other device in its
handle... (a.3) "Ballistic knife" means any knife that has
a blade which is forcefully projected from the handle by
means of a spring-loaded device or explosive charge.
- 18-12-102. Possessing a dangerous or illegal weapon... (1)
As used in this section the term "illegal weapon"
[includes]... gravity knife, or switchblade knife... {or
ballistic knife}. (3) A person who knowingly possesses a
dangerous weapon commits a class 5 felony.
- 18-12-105. Unlawfully carrying a concealed weapon -
unlawful possession of weapons. (1) A person commits a
class 2 misdemeanor if he knowingly and unlawfully:
(a) Carries a knife concealed on or about his person...
(2)... affirmative defense... (a) A person in his own
dwelling or place of business... (b) A person in a private
automobile... (c) [written permit] (d) A peace officer...
Colorado Case Law:
"The definition of 'knife' in subsection (1)(f) of this
section is sufficiently specific to give fair warning of
the proscribed conduct and is therefore constitutional..."
(1992)
