Duty to retreat

A duty to retreat is a legal requirement in some states that a person who is attacked outside the home must avoid using deadly force if he or she can safely escape. Deadly force is justified only if retreat is not possible or would put the person in greater danger.

The rule arises from the common-law principle that killing is a last resort. Under the traditional approach, there is an exception: the castle doctrine excuses retreat in one's own home. Several jurisdictions, such as New York, New Jersey, Massachusetts and some others, apply a duty to retreat in public places, usually with exceptions, while most states have eliminated it through stand-your-ground laws or by case law. Courts have held that retreat is required only if it is safe and known to be available.

Supporters of the rule argue that it values human life by encouraging de-escalation and avoiding unnecessary killings. Opponents argue that it forces victims to take an unrealistic moment-by-moment evaluation of escape routes, and that a person facing an attack should not need to flee. The relationship between the two rules affects trials: prosecutors in duty-to-retreat states may argue that a defendant could have escaped. Statutes also differ on whether the rule applies to non-deadly force.