309 A.2d 579 Commonwealth v. Bayard, Appellant. Supreme Court of Pennsylvania.Argued November 14, 1972 Decided September 19, 1973 Criminal Law — Self-defense — Elements of defense — Duty to retreat — Participation in street fight escalating into a “gang war” — Evidence. 1. In order to successfully invoke the defense of self-defense, (1) the slayer […]