225 Pa. Code § 404 : — RULES OF EVIDENCERELEVANCE AND ITS LIMITS — Character Evidence; Crimes or Other Acts

(a) Character Evidence.
(1) Prohibited Uses. Evidence of a person's character or character trait is not admissible to prove that on a particular occasion the person acted in accordance with the character or trait.
(2) Exceptions for a Defendant or Victim in a Criminal Case. The following exceptions apply in a criminal case:
(A) a defendant may offer evidence of the defendant's pertinent trait, and if the evidence is admitted, the prosecutor may offer evidence to rebut it;
(B) subject to limitations imposed by statute a defendant may offer evidence of an alleged victim's pertinent trait, and if the evidence is admitted the prosecutor may:
(i) offer evidence to rebut it; and
(ii) offer evidence of the defendant's same trait; and
(C) in a homicide case, the prosecutor may offer evidence of the alleged victim's trait of peacefulness to rebut evidence that the victim was the first aggressor.
(3) Exceptions for a Witness. Evidence of a witness's character may be admitted under Rules 607, 608, and 609.
(4) Exception in a Civil Action for Assault and Battery. In a civil action for assault and battery, evidence of the plaintiff's character trait for violence may be admitted when offered by the defendant to rebut evidence that the defendant was the first aggressor.
(b) Crimes, Wrongs or Other Acts.
(1) Prohibited Uses. Evidence of a crime, wrong, or other act is not admissible to prove a person's character in order to show that on a particular occasion the person acted in accordance with the character.
(2) Permitted Uses. This evidence may be admissible for another purpose, such as proving motive, opportunity, intent, preparation, plan, knowledge, identity, absence of mistake, or lack of accident. In a criminal case this evidence is admissible only if the probative value of the evidence outweighs its potential for unfair prejudice.
(3) Notice in a Criminal Case. In a criminal case the prosecutor must provide reasonable notice in advance of trial, or during trial if the court excuses pretrial notice on good cause shown, of the general nature of any such evidence the prosecutor intends to introduce at trial.

225 Pa. Code § 404