Synopsis As Introduced Amends the Criminal Code of 2012. Provides that a person commits unlawful use of body armor when the person knowingly purchases, owns, or possesses body armor if the person has been convicted of a felony that is a crime of violence. Provides that it is an affirmative defense to a violation that the defendant obtained prior written certification from his or her employer that the defendant's purchase, use, or possession of body armor was necessary for the safe performance of lawful business activity. Provides that it is also an affirmative defense to a violation for a confidential informant or witness with a conviction for a crime of violence to possess body armor when that person is engaged or reasonably believes that he or she is engaged by a law enforcement agency for a legitimate law enforcement purpose and is under the direct supervision and acting under the direct authorization of the chief of police of that law enforcement agency or a law enforcement officer designated by the chief of police. Provides that a violation is a Class 4 felony. Defines "crime of violence".