William O'Brien charged with murder in shooting death of Samuel Waters in Mansfield
MANSFIELD – Charges have been upgraded against William O'Brien in connection with the weekend murder of 23-year-old Samuel Waters in Mansfield. At a court appearance Monday, a prosecutor said O'Brien, 22, apologized for the killing.
Police received a 911 call Saturday morning just before 11:15 a.m. for a man suffering from a gunshot wound to the head at a house on West Church Street. When officers arrived, they said O'Brien was in the street wearing body armor and then fled the scene.
"He was found a short time period later. He indicated to police that he apologized for killing Sam and made other statements to the effect that he had just killed someone," said Assistant District Attorney Patrick Driscoll.
Witnesses told police that O'Brien shot and killed Waters. Investigators found numerous firearms and large amounts of money and marijuana in the house. "It's a strong case for the Commonwealth," Driscoll said.
O'Brien, a Manchester-by-the-Sea resident, was initially arrested on charges of carrying an illegal firearm and carrying a loaded illegal firearm. On Monday, the Bristol District Attorney's office announced that O'Brien is now also charged with murder. He is being held without bail.