Offenders under 21 years of age; parole. Provides that any person sentenced to a term of life imprisonment for a single felony offense or multiple felony offenses committed while that person was under 21 years of age and who has served at least 20 years of such sentence and any person who has active sentences that total more than 20 years for a single felony offense or multiple felony offenses committed while that person was under 21 years of age and who has served at least 20 years of such sentences shall be eligible for parole. Under current law, such parole provisions apply only to juvenile offenders.