When a juvenile offender is convicted of a crime, the court shall sentence the defendant to imprisonment in accordance with section 70.05 or sentence him upon a youthful offender finding in accordance with section 60.02 of this chapter.
Subdivision one of this section shall apply when sentencing a juvenile offender notwithstanding the provisions of any other law that deals with the authorized sentence for persons who are not juvenile offenders. Provided, however, that the limitation prescribed by this section shall not be deemed or construed to bar use of a conviction of a juvenile offender, other than a juvenile offender who has been adjudicated a youthful offender pursuant to section 720.20 of the criminal procedure law, as a previous or predicate felony offender under section 70.04, 70.06, 70.08 or 70.10, when sentencing a person who commits a felony after he has reached the age of sixteen.
