MODEL PENAL CODE
(1) No person may be convicted of an offense unless each element of such offense is proved beyond a reasonable doubt. In the absence of such proof, the innocence of the defendant is assumed.
(2) Subsection (1) of this Section does not:
(a) require the disproof of an affirmative defense unless and until there is evidence supporting such defense; or
(b) apply to any defense which the Code or another statute plainly requires the defendant to prove by a preponderance of evidence.
(3) A ground of defense is affirmative, within the meaning of Subsection (2)(a) of this Section, when:
(a) it arises under a section of the Code which so provides; or
(b) it relates to an offense defined by a statute other than the Code and such statute so provides; or
(c) it involves a matter of excuse or justification peculiarly within the knowledge of the defendant on which he can fairly be required to adduce supporting evidence.
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