Prosecutors say Anthony Samora was sentenced Wednesday.
A court ruling last December mandated that Samora was subject to a life sentence based on having a prior conviction for rape.
Prosecutors say Samora has admitted to having sex with children more than 100 times and has been arrested multiple times for sex crimes against children.
Authorities say Samora was out of prison on probation and parole in May 2008 when was accused of raping a 16-year-old developmentally delayed boy he picked up.
Samora was 40 at the time.
He was convicted in 2004 of raping a 14-year-old hitchhiker and served less than three years behind bars.