The long, complicated history of self-defense laws in the US

Last Friday, a Wisconsin jury acquitted Kyle Rittenhouse of criminal charges related to the murder of two protesters. In that case, Rittenhouse succeeded in claiming self-defense, and it has given rise to a national conversation about the rules surrounding self-defense. Daniel Medwed, GBH News legal analyst and Northeastern law professor, joined host Henry Santoro on Morning Edition to discuss. This transcript has been edited for clarity and length.

Henry Santoro: There were understandably a lot of strong reactions to the Rittenhouse decision, and they're still coming in. What were some of the key features of that type of defense? And what does that defendant usually have to show in a case like this?

Daniel Medwed: Self-defense is what's known in criminal law as a justification defense, where you admit committing the crime, but claim that you were in the right — that you were justified in doing so. And while the law varies considerably from state to state, there tend to be three chief overlapping features.

First, reasonableness, you have to show that you reasonably believed you were facing a threat. Second, imminence, that threat has to be immediate. It has to be looming. Third, proportionality, you have to respond with commensurate threat of force or at least an amount of force that's proportional to the amount that you're facing. You can't take out a gun and shoot someone if they're about to launch a spitball in your face. There has to be an evenness there. So those are the three overlapping characteristics: reasonableness, imminence and proportionality.

Santoro: And what about a situation like in this Rittenhouse case where — this kid crossed state lines, he had a firearm almost looking for a fight. Does the defendant's behavior factor into the self-defense question?

Medwed: It does it. And here's how it might. So, it could impact the assessment of reasonable belief. If you come looking for a fight, then maybe your perception of a threat is really a pretext for vigilantism, and that's something that could be part of the equation. Another way that it factors in is its relation to something called the initial aggressor rules.

And here's how that works. So, on the one hand, if you're the initial aggressor, you pick the fight, you usually relinquish or give up any right to self-defense. You can't start a fight. And then when the other party gets the upper hand, you draw on superior force and claim self-defense. That's just not fair. It would incentivize baiting, baiting people into fights.

On the other hand, if you, as an initial aggressor, legitimately and truly withdraw from the encounter, you communicate that and then you act in a way that indicates that you're abandoning it. Maybe you backpedal or raise your hands. Then, in some jurisdictions, you can reclaim your right to self-defense. It really varies from state to state, and it's pretty complicated.

Santoro: Did the prosecution botch this case?

Medwed: I think there's an argument that they did in some ways. Especially — there was a reference to Rittenhouse's post-arrest silence, which is really a no-no, a constitutional no-no, for at least the last half century.

Santoro: But isn't there also a duty for you to retreat before using self-defense? How does that work?

Medwed: Well, back in the days of yore in Ye Olde England, there was no duty to retreat, based partially on a male-oriented view of the world that you don't have to cede an inch, you can just stand your ground. But over time, we became more enlightened, and we recognized that the best way to decrease violence on the whole is to impose a duty to retreat. And what that means is before you can draw upon defensive force, you have to retreat, but only if you can do so safely. That's the key piece of it. You don't have to retreat if it's unsafe to do so.

Santoro: Got it. But what about if you're in your own home or if you're in your office and someone comes in and the situation in that case, how do you treat it?

Medwed: In jurisdictions that recognize a duty to retreat, Henry, usually there's an exception when you're in your home or, in my wife's home state of Nebraska, if you're in the office place. It's called the Castle Exception — that we're all kings and queens of our castle, there should be a place, a refuge where we don't have to flee. The problem is, of course, it might be convenient to use force while in the comfort of your own home, but perhaps unnecessary. So, there are some complications.