( CNN ) -- People convicted of certain sex offenses against a child in California will get life in prison without parole starting Thursday , after Gov . Arnold Schwarzenegger signed `` Chelsea 's Law . '' The law was named for 17-year-old Chelsea King , who was murdered this year by a registered sex offender who also admitted having killed 14-year-old Amber Dubois . `` Because of Chelsea , California children will be safer , '' Schwarzenegger said . `` Because of Chelsea , this never has to happen again . '' The `` one-strike '' provision applies to forcible sex crimes against minors that include aggravating factors , such as the victim 's age or whether the victim was bound or drugged . The unanimous passage of the bill by California lawmakers was a rare display of bipartisanship , spurred by outrage over the King and Dubois murders . It included an urgency clause that made it immediately effective . `` Very few things bring Democrats and Republicans together these days , but your daughters have , '' Schwarzenegger said to their parents before signing the law in a San Diego ceremony . Kelly King , Chelsea 's mother , spoke after the governor . She thanked lawmakers for inspiring `` our next generation of voters by your actions . '' `` You 've shown them what is good and right and sound decision making in government , '' King said . The measure also puts those convicted of certain sex crimes against minors on lifetime parole . Registered sex offender John Gardner III admitted last March to the killings . A few days after King 's body was found , Gardner led authorities to the remains of Dubois , who had been missing for more than a year . Gardner was sentenced in April to three consecutive terms of life without parole for the murders and an attack on a jogger in a plea deal that spared him the death penalty .
An urgency clause makes the law immediately effective . The law was named for a teen murdered by a registered sex offender . Chelsea 's killer also admitted killing Amber Dubois .