Affirmative Defences (Criminal): Burden of going forward, or burden of persuasion?

In the U.S., how are affirmative defences handled in the criminal system? Does the accused have a burden of persuasion, or simply a burden of going forward? What are the due process implications?


I don’t practice criminal law, but my vague memory from the bar exam is that the defendant must make a prima facie showing that a defense applies, and then the state bears the burden of persuasion.

Is that for all defences, or just the negative ones?

I’ve heard that in some jursidictions, the onus in affirmative defences is on the accused. My Black’s gives “insanity, intoxication, self-defense, automatism, coercion, alibi and duress” as examples of affirmative defences.

So my question is whether the principle you’ve cited (defence needs only to make a prima facie case) applies to these defences as well, or if there is actually an onus on the accused to prove them, because they are defences which are in the peculiar knowledge of the accused?

In Texas, there are defenses and affirmative defenses. If evidence of a defense has been admitted, it is placed in the jury instruction, and the state is required to disprove the defense beyond a reasonable doubt. If the jury has a reasonable doubt regarding the defense, it must acquit the defendant. Self defense, for example, is a defense. If evidence has been admitted regarding self defense in an assault case, the prosecution must disprove that the defendant was reasonably defending himself beyond a reasonable doubt.

With an affirmative defense, however, the burden shifts. If an affirmative defense is raised, the defendant must prove it to the jury by a preponderance of the evidence. Insanity is an example of an affirmative defense.

pravnik’s post accurately describes the situation in Virginia as well.

It’s worth mentioning, as I just did in another thread, that entrapment can give rise to both sides of this coin. Entrapment is an affirmative defense; the defense must prove it by preponderance of the evidence. But if the defense does show that government actually induced the accused to commit the crime, the burden then shifts to the government to show, beyond a reasonable doubt, that the accused was predisposed to commit the crime.

Apparently Arizona has a different rule:

So does Connecticut:

Georgia too:

With respect to due process, the Supreme Court has held that the prosecution only needs to prove the elements of a crime beyond a reasonable doubt. Legislatures are pretty much free to define crimes as they want, and to establish affirmative defenses. Defendants can be required to prove their affirmative defenses. The only limit is that they can’t be required to disprove defined elements of the crime.

Interesting. The Supreme Court of Canada has gone the other way, and held that placing a burden of persuasion on the accused infringes the presumption of evidence, regardless whether the point in issue is an element of the offence or a defence: R. v. Whyte, [1988] 2 S.C.R. 3: