“WTOP’s American Nightmare Series” is a podcast covering true crime stories in the Washington D.C. region.  Season 3, "Unknown Subject": For 9 years, he terrorized women across the DC region. Breaking into homes and raping his victims before killing a brilliant scientist near the gates of Georgetown University in 1998. And then, it all stopped. Had he died? Was he locked up? Before the FBI would name him the infamous Potomac River Rapist, detectives simply called him their “unknown subject” for years. A man whose DNA linked him to multiple crime scenes but whose name and face remained a...