Forget George Zimmerman and Trayvon Martin. Forget any specific case. You’re going to design the best society you can, and I’m going to offer you two (and only two) options for a self-defense law.
A person may use deadly force in self-defense if he or she reasonably believes that deadly force is necessary to prevent imminent death or great bodily harm, but may not resort to deadly force without first using every reasonable means within his or her power to avoid the danger, including retreat.
A person may use deadly force in self-defense if he or she reasonably believes that deadly force is necessary to prevent death or great bodily harm. The person who is not engaged in an unlawful activity and who is attacked in any place where he or she has a right to be may meet force with force, and has no duty to retreat.
Which law do you choose for your better society, and why?
On the one hand, life is precious; there is some appeal to the idea that before using force that one should, as a matter of principle, do everything reasonable to avoid having to end another human being’s life.
On the other hand, when people are going about their lawful business, attackers—lawbreakers—should not, as a matter of principle, be able to force them to flee. Free people stand their ground.
If I thought I was threatened with deadly force and I had a reasonable avenue of retreat I like to think that I would take it. I think that’s the right course. But if I were attacked in a public place I wouldn’t want to turn my back on my attacker, and I wouldn’t want my future depending on a jury in a well-lighted courtroom judging whether I should have done so. I would allow the person attacked in a public place to meet force with force.
The first is the common-law rule. The second is a paraphrase of the rule as modified with Florida’s 2005 “stand your ground” law. By its terms it only applies to a person who is attacked in a public place, though the Florida appellate case of Williams v. State applies it without discussion in a case that doesn’t appear to have involved an attack.