In August 2011, Pennsylvania amended the "Use of Force in Self Protection" statute located at section 505 of the Pennsylvania Crimes Code to include a watered down version of the "stand your ground" law. The major difference between the new stand-your-ground provisions and the old self-defense law centers around the duty to retreat before employing deadly force, when an actor is outside of his home or place of employment. The stand-your-ground law eliminates the duty to retreat, but only under limited circumstances.
The Pennsylvania stand-your-ground law allows a person to use deadly force against an assailant as long as all of the following circumstances apply: 1) the actor is not engaged in illegal activity, 2) the actor is not in illegal possession of a firearm, 3) the actor has a right to be in the place where he was attacked, 4) the actor believes it is immediately necessary to use deadly force in order to protect himself from death, serious bodily injury, kidnapping or rape, and 5) the person against whom the deadly force is employed is armed with either a firearm, a realistic replica firearm or any other lethal weapon.
The key difference between Pennsylvania's watered-down stand-your-ground law and the stand-your-ground law of some other states is the requirement that the actor be threatened with a deadly weapon before he may lawfully employ deadly force outside his home or place of work. Thus, in Pennsylvania, if an unarmed assailant starts throwing punches, the victim of the assault may not lawfully pull out a gun and shoot the attacker. Instead, traditional self-defense law applies, which gives the victim two options: 1) meet the attacker's force with equal force, i.e. throw punches back, or 2) retreat. If retreat is impossible, an actor may respond with deadly force against an unarmed attacker, if he or she believes that death or serious bodily injury is imminent. For example, a 100 pound woman cornered in an alley by an unarmed 250 pound man, who is bashing her into a wall with one hand, while trying to rip her clothes off with his other hand, would certainly have a very strong self-defense argument if she pulled out a gun and shot him, as the attacker in this scenario is capable of killing or seriously injuring the victim with his bare hands, not to mention the fact that he is trying to sexually assault her. In fact, I cannot envision any police department charging a female victim in such a scenario.
There is never a duty to retreat if the attacker is armed with a deadly weapon and the victim/actor fears death or serious bodily injury. For example, if a would-be mugger pulls out a knife and threatens to stab the vicitm if he does not hand over his wallet, the would-be victim need not choose between handing over his wallet or running away. Instead, he can opt to pull out his pistol, and do the world a public service by eliminating the knife-wielding thug from society. Scenarios like this are why stand-your-ground laws are necessary.
Matt McClenahen is a criminal defense lawyer in State College, Pennsylvania, with extensive experience in self-defense cases. He limits his practice to criminal defense. http://www.mattmlaw.com/Criminal-Defense-Overview/Assault-Defense.shtml