Prosecutors say a teenage girl witnessed the fatal stabbing of her friend\'s mother in their Burlington, Mass., home via online video. Christopher Piantedosi, 39, is accused of stabbing his ex-girlfriend, Kristen Puliscano, 38, in their daughter\'s bedroom last Thursday. Piantedosi was ordered held without bail pending trial and is barred from contact with his two children. He has pleaded not guilty to murder charges, and will appear in court for a probable cause hearing June 7, The Boston Globe reported. Piantedosi, whose relationship with Puliscano had recently soured, allegedly appeared unannounced at Puliscano\'s home. While the two argued in the kitchen, their 15-year-old daughter was in her room video chatting with a friend. When she heard the argument, she went into the kitchen to find Piantedosi with a knife in his hand. Prosecutor Nicole Allain said the girl allegedly asked Piantedosi: \"What, are you trying to kill Mom?\" Court documents say Piantedosi then ran after Puliscano, who fled to her daughter\'s room and tried to block the door. Piantedosi forced his way in and allegedly tackled Puliscano to the bed and stabbed her 34 times with both a knife and a meat cleaver, screaming \"You gotta die,\" while Puliscano cried \"Chris, please stop. I love you.\" All the while, prosecutors believe their daughter\'s friend watched via the video connection. Piantedosi was arrested the next day after driving to police barracks. \"Welcome to the worst aspect of the 21st century: cyber horror and its progeny,\" said defense attorney Jeffrey Denner. \"This is just one more step in a horrible direction.\" Prosecutors said if the video was saved to a hard drive, it could be entered as evidence. If it is not, the friend could testify as a witness, the Boston Herald reported. Prosecutors said Piantedosi has a history of mental health issues and there allegedly previous incidents of violence between him and Puliscano.