The Pennsylvania Supreme Court extended the no-retreat dwelling house exception to the self-defense rule by holding that a person in his place of business may lawfully resist an intruder with the use of deadly force even though a way of escape is available.
Commonwealth v. Johnston, 438 Pa. 485, 263 A.2d 376 (1970).
Commonwealth v. Johnston' is an innovative decision which limits the duty to retreat in cases of self-defense. The facts of the case are simple. The defendant Johnston shot and killed a man named Pittman while Pittman was on defendant's business premises as a social guest.
J. K. Lewis,
Criminal Law - Homicide - Self-Defense - The Duty to Retreat,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol9/iss2/14