Actor Tom Sizemore's domestic violence case is heating up. The star of CBS's defunct Robbery Homicide Division already faces charges for assaulting an ex-girlfriend and intimidating a witness in the case. Now, Celebrity Justice reports he's been arrested again, this time for threatening another potential witness — his ex-fiancée Heidi Fleiss. Sizemore allegedly left a message on the Hollywood Madam's answering machine, threatening to "knock out her teeth, kill her and harm members of her family" if she testified against him. He was released on $100,000 bail early Friday.