SAN DIEGO -- Gov. Arnold Schwarzenegger Thursday signed legislation named for slain Poway High School senior Chelsea King that he said will better protect California's children.

The governor put his signature to Assembly Bill 1844, known as "Chelsea's Law," during a ceremony at the Spreckels Organ Pavilion in Balboa Park.

"Because of Chelsea, everyone has joined together to solve this serious problem in our state," Schwarzenegger said. "Because of Chelsea, California's children will be safer. Because of Chelsea, this never has to happen again."

The bill, authored by Assemblyman Nathan Fletcher, R-San Diego, requires a life sentence without the possibility of parole for forcible sex acts against minors. It also tightens sex offense parole guidelines and requires lifelong tracking of certain sex offenders.

Fletcher said Chelsea's Law -- which goes into effect immediately -- puts California at the forefront in dealing with violent sex offenders.

"We are about to see signed into law a sweeping piece of legislation that will better protect our children, who are the most vulnerable, the most innocent, the most precious," Fletcher said. "Today is a very good day for them."

The legislation creates a "true one-strike life without the possibility of parole charge" for violent sex offenders who prey on children, he said.

"Because, if you don't believe you can rehabilitate someone that violently sex offends a child, you should not let them out, and today California will adopt this," he said.

Fletcher thanked members of the state Senate and Assembly, who unanimously approved the legislation.

Schwarzenegger and Fletcher were joined at the ceremony by Chelsea's parents.

Brent King said Chelsea's Law will fix California's "broken system" and ensure that the "worst of the worst violent child predators" are locked up for life.

Both thanked legislators and the governor for quickly passing Chelsea's Law.

"Our children look to us for guidance and understanding of how our world should be," Kelly King said. "In supporting and passing Chelsea's Law, you have shown them what is good and right and sound decision-making in government."

Also taking part in the bill signing ceremony were San Diego Mayor Jerry Sanders, Assembly Speaker John Perez, D-Los Angeles, and Sen. Dennis Hollingsworth, R-Murrieta.

Chelsea was raped and killed Feb. 25 by registered sex offender John Albert Gardner III, who grabbed her while she was jogging at a Rancho Bernardo park. Searchers found the 17-year-old student's body a few days later in a shallow grave on the shore of Lake Hodges.

Gardner, 31, was sentenced in May to two life terms without parole for murdering and sexually assaulting Chelsea and abducting, raping and fatally stabbing 14-year-old Amber Dubois of Escondido a year earlier.

A package of bills promoted by Amber's father, and intended to improve law enforcement handling of missing person cases, also await the governor's signature.