Bill Cosby: Why is there a time limit on bringing sexual assault cases to US courts?

More than 50 women allege they have been sexually assaulted by the comedian Bill Cosby, but only one woman will face him in criminal court. Campaigners say laws which set deadlines on when these crimes can be reported, deny survivors justice.
Fifty years later, Kevin Sweeney is finally able to talk about the sexual abuse to which he was subjected.
"It quickly escalated to inappropriate touching, and eventually rape," explains Mr Sweeney.
It continued until Mr Sweeney was 13 years old. His abuser threatened to harm his siblings and parents if he told anyone, so he stayed silent.
Now a school teacher, married with children, Mr Sweeney lived with his secret for decades.
In his early forties, after learning his abuser had died, he worked up the courage to tell his wife.
By then, it was too late to seek justice - even if his attacker had been alive, he could not have pressed charges, thanks to the statute of limitations on such crimes in his home state.
Statutes of limitation set deadlines on when someone can file a criminal complaint.
In murder cases there is no time frame, but for many other crimes, the clock starts ticking after an alleged offence occurs. When it comes to allegations of rape and sexual assault, states have different laws. The window of opportunity can vary from a few years, to a few decades. In sixteen states there is no limit.
Campaigners say this law has impeded many of those who are accusing Bill Cosby from seeking justice. Proponents say it's necessary to keep the justice system fair.
Fifty-eight women have come forward claiming Mr Cosby sexually assaulted them - allegations spanning from the 1960s to the late 2000s.
Only one of these women has brought charges against Mr Cosby.
"For most of these accusations, it was simply too late for a prosecutor to even consider them," Gloria Allred, the lawyer representing more than 30 of the women, recently wrote.
Mr Cosby is due to go on trial in June next year, accused by Andrea Constand of drugging and abusing her in Pennsylvania in January 2004. He denies the allegations and all the others.
Ms Constand first went to the police in 2005, but prosecutors initially said there wasn't enough evidence to press charges.
Last year the case was reopened, after new evidence emerged. Ms Constand filed her case a few days before the statute of limitations - which is 14 years in Pennsylvania - was about to expire.
But other women who accuse Mr Cosby of sexual assault say they feel cheated.
Lise-Lotte Lubin says she passed out after Mr Cosby gave her two alcoholic drinks and petted her hair at a hotel in Nevada in 1989. She believes she was drugged by the comedian.