Connecticut General Statutes Title 53A. Penal Code § 53a-12. Defenses; burden of proof

(a) When a defense other than an affirmative defense, is raised at a trial, the state shall have the burden of disproving such defense beyond a reasonable doubt.

(b) When a defense declared to be an affirmative defense is raised at a trial, the defendant shall have the burden of establishing such defense by a preponderance of the evidence.