Defendant's conviction for possession of body armor by a person previously convicted of a violent felony, with prior serious felony and prior prison term findings, is reversed where: 1) Penal Code section 12370 must be construed to contain a knowledge element and the prosecution had to prove that defendant knew, or reasonably should have known, the body vest in his possession had characteristics making it illegal under section 12370; and 2) section 12370 is unconstitutionally void for vagueness because it does not provide fair notice of which protective body vests constitute the body armor made illegal by the statute.