Notwithstanding any other provision of law, if a defendant is found guilty of any non-homicide crime for which the only sentence provided by law is life imprisonment without the possibility of parole and that defendant proves by a preponderance of the evidence that he or she was under the age of 18 years at the time of the offense, the sentence shall be life imprisonment.
Ala. Code § 13A-5-43.1 (1975)