Missouri:
- Switchblades that violate the federal switchblade act are illegal
- Maximum legal blade length for a concealed knife is 4" or less
- Open carry of any knife is not restricted (except see switchblade above)
- Laws are the same for minors as adults
from:
Concealment: Missouri law prohibits the concealed carry of any knife, except for “an ordinary pocketknife” with a blade not more than four (4) inches in length. The Missouri statutes provide as follows:
- A person commits the crime of unlawful use of weapons if he or she knowingly:
(1) Carries concealed upon or about his or her person a knife , a firearm, a blackjack or any other weapon readily capable of lethal use;
The statutory definition of “knife” is: any dagger, dirk, stiletto, or bladed hand instrument that is readily capable of inflicting serious physical injury or death by cutting or stabbing a person. For purposes of this chapter, ‘knife’ does not include any ordinary pocketknife with no blade more than four inches in length;
Note: the term “ordinary pocketknife” is ambiguous and subject to varying interpretations by law enforcement.