Cosby unlikely to face charges over sex abuse claims

In recent weeks, about 20 women have come forward to accuse veteran U.S. comedian Bill Cosby of sexual assault and even rape.

But with most of the alleged attacks now more than 10 years in the past, the 77-year-old Emmy and Golden Globe winner - who has repeatedly denied any wrongdoing - is unlikely to face criminal charges due to statutes of limitations.

The legendary star of "The Cosby Show" and "I Spy" was the subject of a civil suit brought in 2005 by 15 women, 13 of whom remained anonymous. A settlement was reached in 2006 with one of the plaintiffs.

The following is a look at the allegations against Cosby, and the legal parameters surrounding them:   

The allegations against Cosby date back to the 1960s, and the encounters took place in several U.S. states including New York, New Jersey, Pennsylvania and California.

 In America, laws vary from state to state in terms of the gravity of the crime, the burden of proof, the length of the statutes of limitations and the possible punishments.         

An act of rape "by forcible compulsion" in New York can be considered to be an "illegal sexual relationship" in California, and thus the punishment is less severe.                         

Most of the allegations go back to the 1970s and 1980s. In the states involved, the statutes of limitations bar charges from being brought, except in Pennsylvania, where an alleged victim has 12 years to file a criminal complaint.        

In the East Coast state, Andrea Constand, former director of operations of the women's basketball team at Temple University, has accused Cosby of drugging and sexually assaulting her in 2004.        

A year later, prosecutors decided not to file criminal charges...