Exclusive Witness Claims She Saw the "Grim Sleeper" Serial Killer Oxygen Insider Exclusive! Create a free profile to get unlimited access to exclusive videos, breaking news, sweepstakes, and more! Sign Up for Free to View Witness Claims She Saw the "Grim Sleeper" Serial Killer A woman came forward to say she saw the killer shoot a victim and cover her up with a mattress. She had a name, too. Was she on the right track? Watch the Full Episode
