Sec. 25.00  Defenses; burden of proof.
    1.   When a "defense, " other than an "affirmative defense, "
defined by statute is raised at a  trial,  the  people  have  the
burden of disproving such defense beyond a reasonable doubt.
    2.   When a defense declared by statute to be an "affirmative
defense" is raised at a trial, the defendant has  the  burden  of
establishing such defense by a preponderance of the evidence.
.

(For verification consult Official Text at Senate Gopher site.)