About 200,000 people are serving life sentences across the United States. Nearly 70,000 people serving life sentences were under 25 — either youths or “emerging adults” — at the time of their crimes. About one-third of them are serving life without any chance of parole. In some states — California, Arkansas, Louisiana, Michigan, Pennsylvania, Connecticut and Massachusetts — about half or more of their "lifers" prison population were under age 25 at the time of the offense.