Self-defense is what lawyers call an “affirmative defense” to a homicide charge. Most people are familiar with the concept of “innocent until proven guilty.” But in a self-defense case, the accused is clearly guilty of a homicide: I mean, for God’s sake, they killed someone. The burden of proof therefore shifts to the clearly guilty person to “justify” that homicide. The law will allow people to argue a number of justifications, but self-defense is the most basic.
