Sec. 21a.
(1) It is an affirmative defense to a prosecution for a criminal offense that the defendant was legally insane when he or she committed the acts constituting the offense. An individual is legally insane if, as a result of mental illness as defined in section 400 of the mental health code, 1974 PA 258, MCL 330.1400, or as a result of having an intellectual disability as defined in section 100b of the mental health code, 1974 PA 258, MCL 330.1100b, that person lacks substantial capacity either to appreciate the nature and quality or the wrongfulness of his or her conduct or to conform his or her conduct to the requirements of the law. Mental illness or having an intellectual disability does not otherwise constitute a defense of legal insanity.
(2) An individual who was under the influence of voluntarily consumed or injected alcohol or controlled substances at the time of his or her alleged offense is not considered to have been legally insane solely because of being under the influence of the alcohol or controlled substances.
(3) The defendant has the burden of proving the defense of insanity by a preponderance of the evidence.
History: Add. 1975, Act 180, Eff. Aug. 6, 1975 ;-- Am. 1994, Act 56, Eff. Oct. 1, 1994 ;-- Am. 2014, Act 76, Imd. Eff. Mar. 28, 2014
Structure Michigan Compiled Laws
Chapters 760 - 777 - Code of Criminal Procedure
Act 175 of 1927 - The Code of Criminal Procedure (760.1 - 777.69)
175-1927-VIII - Chapter VIII Trials (768.1...768.37)
Section 768.1 - Speedy Trial; Right of Parties; Duty of Public Officers.
Section 768.2 - Criminal Cases; Precedence; Adjournment; Continuance.
Section 768.3 - Person Indicted; Presence at Trial.
Section 768.4 - Proof of Felony at Trial for Misdemeanor; Effect.
Section 768.5 - Defendants Jointly Indicted; Separation of Trials.
Section 768.6 - Commission of Offense in Certain State Institutions; Penalty.
Section 768.8 - Issues of Fact to Be Tried by Jury; Waiver of Trial by Jury.
Section 768.9 - Challenge to Juror for Cause; Membership on Grand Jury.
Section 768.11 - Repealed. 1978, Act 11, Imd. Eff. Feb. 8, 1978.
Section 768.12 - Peremptory Challenge; Offense Not Punishable by Death or Life Imprisonment; Number.
Section 768.13 - Peremptory Challenge; Offense Punishable by Death or Life Imprisonment; Number.
Section 768.14 - Jurors; Form of Oath.
Section 768.15 - Jurors; Affirmation in Lieu of Oath.
Section 768.16 - Jurors; Liberty; Oath and Duty of Officer in Charge.
Section 768.17 - Jurors; Medical Attendance; Use of Newspapers and Letters.
Section 768.19 - Perjury; Acts of Officer Under Oath.
Section 768.21a - Persons Deemed Legally Insane; Burden of Proof.
Section 768.21c - Use of Deadly Force by Individual in Own Dwelling; "Dwelling" Defined.
Section 768.23 - Exception; Necessity of Taking.
Section 768.24 - Evidence; Leading Question.
Section 768.25 - Evidence; Proof of Signature.
Section 768.26 - Evidence; Use of Former Testimony; Deposition for Defendant.
Section 768.27 - Evidence; Proof of Intent or Motive by Similar Acts.
Section 768.28 - Evidence; View by Jury.
Section 768.29 - Judge's Duty at Trial; Effect of Failure to Instruct.
Section 768.29a - Defense of Insanity in Criminal Action Tried Before Jury; Instructions.
Section 768.30 - Exception to Charge or Refusal to Charge; Necessity.
Section 768.31 - Joint Defendants; Discharge for Insufficient Evidence.
Section 768.33 - Offense Consisting of Different Degrees; Subsequent Trial Prohibited.
Section 768.34 - Discharged or Acquitted Prisoner; Liability for Costs or Fees.
Section 768.35 - Plea of Guilty; Investigation by Judge; Sentence; Refusal to Accept.