Denver Broncos rookie cornerback Perrish Cox could be facing life in prison if convicted on sexual assault charges filed by prosecutors last week.The Associated Press reports that documents unsealed on Tuesday indicate that the charges are Class 3 and Class 4 felonies, which carry a sentence of two years to life in prison.The alleged sexual assaults occurred on October 28, the day the Broncos left for London to play the San Francisco 49ers.