In an insanity plea, why is the burden of proof transferred to the defense?

You are saying that you are guilty of the crime but should not be punished because you did not know the difference between right and wrong. It is now up to YOU to prove this claim. Just because you were "insane" at the time of the crime does NOT mean you are not guilty BECAUSE of that insanity.

In other words, just being insane is not enough to plead Not Guilty by reason of insanity. You must prove you did not KNOW you were doing wrong.

I'd guess it's because the burden of proof is on the prosecution when the question is whether the defendant did the crime he's charged for.

When he pleads insanity, he's admitting he did it. The only question then is what's going to be done with him.

That's a different question from the first one, and there's no legal tradition of requiring the prosecution to prove he's not crazy, nor should there be.

I'd guess. Maybe there's a lawyer around here who isn't busy counting his exorbitant fees or something

It is called an "affirmative defense", meaning the defendant has the burden of proving the facts to support it, once the case-in-chief has been proven by the prosecution.

The defenses of the case-in-chief involve creation of reasonable doubt that all elements of the crime have been proven by the prosecution. The affirmative defense must then be proven "more likely than not", in order to succeed.

If it's a criminal case and the defendant is claiming they were so out of touch with reality by reason of mental defect, when they committed the crime,the burden of proof is on the defendant to prove that they truly were that ill.

However the burden of proof that the defendant committed the crime, and IS responsible for their own actions, is still on the prosecutor.

Insanity is not the crime. If the defense wants to claim it, then it will have to present compelling evidence. The prosecution is not going to assist in that since it has nothing to gain.

The prosecution is saying you committed the crime, that is what they are wanting to prove. The Defense is saying yes, BUT because you were crazy. Why should the prosecution prove you are crazy? It's same as saying you killed in self-defense. The prosecution would be saying you killed, but you are saying you had extenuating circumstances. Why should they prove your case?

Because a Judge or Jury is more inclined to believe a presumption of guilt, than innocence. It's very important to only present factual evidence within a court setting.

Because it is almost impossible to prove "sanity" let alone "in sanity" and the Prosecution is not stupid to lose on that grounds every time.

If you don't believe me, try defining sanity.