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SENSELESS TRAGEDY REAPED IN SUPERIOR COURT

Kingston Culprit Sentenced to Life Imprisonment Following Guilty Plea for Fatal Shooting of Roommate

WILLIAM O’BRIEN — Pled guilty in Fall River Superior Court to second-degree murder and firearm offenses; sentenced to life in prison.

KINGSTON, MA — A 25-year-old Kingston man has been sentenced to life in prison following a guilty plea for the 2023 fatal shooting of his roommate.

William O’Brien pleaded guilty in Fall River Superior Court on September 10 to Second-Degree Murder and Possession of a Large Capacity Firearm and Ammunition. The Honorable Thomas Perrino sentenced O’Brien to life with parole eligibility at 22 years for the murder charge, alongside a concurrent 2.5 to 5-year sentence for the firearms charge. The case was prosecuted by Assistant District Attorneys Patrick Driscoll and Daniel Walsh.

The sentencing brings closure to the May 20, 2023, killing of 23-year-old Samuel Waters. Mansfield Police responded to a reported shooting at 42 West Church Street just after 11:00 a.m., where they found Waters at the base of an internal staircase suffering from multiple fatal gunshot wounds to the head.

O’Brien was located a short distance from the residence wearing a bulletproof vest. Once secured in the back of a police cruiser equipped with audio and video recording, O’Brien made a rambling statement admitting to the killing and directing officers to the discarded weapon. Police recovered a 9mm Polymer 80 caliber semi-automatic pistol from an adjacent brook. The weapon, certified as a large-capacity firearm, had a 31-round capacity and was loaded with 18 rounds.

Investigators determined that O’Brien, Waters, and several friends in their early twenties shared the single-family home. A search of the residence revealed multiple firearms and evidence of a marijuana distribution operation.

Evidence established that O’Brien was sitting on a first-floor couch when Waters came down the stairs. With no clear triggering event, O’Brien stood up and began shooting. In his cruiser statements, which authorities described as sometimes incoherent, O’Brien claimed he believed Waters was going to kill him. Prosecutors noted there is no known evidence to support this belief and acknowledged O’Brien has a history of mental illness.

At the time of the shooting, O’Brien was already serving a two-year committed probation sentence out of Plymouth Superior Court for a prior firearms offense. Following his arrest for the murder, he assaulted a corrections officer while in custody, receiving an additional 90-day sentence. He did not receive time credit for those sentences in this case.

“This was a senseless killing of a young man who had his whole life ahead of him,” District Attorney Tom Quinn stated. “The defendant clearly needs to be incarcerated for a very long time.”