Firearms and Other Dangerous Weapons. A person is guilty of criminal possession of a weapon in the third degree.New Yorkers should call 1-855-LAW-GUNS for questions about guns or assistance with form submissions. A law prohibiting minors under the age of 16 from possessing certain weapons, including air guns, spring-powered guns, and dangerous knives. Even if not actual offenses involving weapons, it is a crime in New York to illegally possess ammunition in violation of Penal Law 265.37 and NYC Admin. Criminal possession of a weapon in the fourth degree is a class A misdemeanor if convicted you could be sentenced to up to 1 year in jail. Facing firearms, knives and weapons possession charges? Meet with Manhattan weapons possession lawyer Peter Katz in a free consultation. New Yorkers should call 1-855-LAW-GUNS for questions about guns or assistance with form submissions. Only a person age 21 or older can be granted a permit to purchase and possess a firearm.