Pennsylvania law, as does federal, permits a person accused of a crime to "defend" in part by proving their "good" character, limited to the pertinent trait. If the crime is robbery or assault, the defense is that the accused is nonviolent; and if the crime charged is forgery or theft, that the person is honest. The method of proof is by reputation—the character witness details what they have heard about the accused, with the typical response being "everyone says" or "people say" that defendant X is [fill in the trait].