The move was inspired by accusations against the entertainer Bill Cosby
California has abolished the time limit for charges of rape and child molestation to be filed, in a move inspired by accusations against the entertainer Bill Cosby.
Jerry Brown, the state's governor, signed a bill into law eliminating the 10-year statute of limitations on allegations of some sexual offences.
The Justice for Victims Act was introduced after dozens of women came forward accusing Cosby of sexual assault.
Many of the claims dated back decades and none have led to charges in California.
Three of the accusers gave evidence in support of the bill.
Currently, rape and child sexual abuse charges need to be filed within 10 years. Allegations of sex crimes against minors have to be prosecuted before they turn 40.
The changes will take effect in January but will not affect any of those who have made allegations against Cosby.
The 79-year-old star, for decades known as 'America's Dad' for his role in 'The Cosby Show', has repeatedly denied the allegations made by dozens of women, many of whom say they were drugged before being sexually assaulted.
He is facing trial next year in Pennsylvania over an allegation of sexual assault from 2004.
In addition, a civil case in California, brought by a woman who claims she was molested at the Playboy Mansion in 1974, when she was 15, has seen the star give evidence under oath.
Lawyer Gloria Allred, who represents the accuser in the civil case and a number of other women who have made claims against Cosby, welcomed the new bill.
She said: "The passage of this new law means that the courthouse doors will no longer be slammed shut in the face of rape victims.
"It puts sexual predators on notice that the passage of time may no longer protect them from serious criminal consequences for their acts of sexual violence."
Seventeen other US states have no statute of limitation on rape. Colorado and Nevada have increased the time available to seek charges in the wake of the allegations against Cosby.
California state senator Connie Leyva, who introduced the bill, said it "tells every rape and sexual assault victim in California that they matter and that, regardless of when they are ready to come forward, they will always have an opportunity to seek justice in a court of law.
"There must never be an expiration date on justice."
But civil rights groups say extending the time limit could lead to false convictions as evidence disappears and memories fade among victims and witnesses.
They say it is unfair to expect a suspect to recall alibis decades later.