MODEL PENAL CODE
(1) A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity either to appreciate the criminality [wrongfulness] of his conduct or to conform his conduct to the requirements of law.
(2) As used in this Article, the terms "mental disease or defect"
do not include an abnormality manifested only by repeated criminal or otherwise
Section 4.10. Immaturity Excluding Criminal Convictions; Transfer of Proceedings to Juvenile Court.
(1) A person shall not be tried for or convicted of an offense if:
(a) at the time of the conduct charged to constitute the offense he was less than sixteen years of age [, in which case the Juvenile Court shall have exclusive jurisdiction*]; or
(b) at the time of the conduct charged to constitute the offense he was sixteen or seventeen years of age, unless:
(i) the Juvenile Court has no jurisdiction over him, or,
(ii) the Juvenile Court has entered an order waiving jurisdiction and consenting to the institution of criminal proceedings against him.
(2) No court shall have jurisdiction to try or convict a person of an offense if criminal proceedings against him are barred by Subsection (1) of this Section. When it appears that a person charged with the commission of an offense may be of such an age that criminal proceedings may be barred under Subsection (1) of this Section, the Court shall hold a hearing thereon, and the burden shall be on the prosecution to establish to the satisfaction of the Court that the criminal proceeding is not barred upon such grounds. If the Court determines that the proceeding is barred, custody of the person charged shall be surrendered to the Juvenile Court, and the case, including all papers and processes relating thereto, shall be transferred.
* The bracketed words are unnecessary if the Juvenile Court Act so provides or is amended accordingly.