Man convicted of killing fellow inmate at Massachusetts Treatment Center in Bridgewater

PLYMOUTH – Plymouth County District Attorney Timothy Cruz has announced that a man has been convicted of fatally beating a fellow inmate at the Massachusetts Treatment Center in Bridgewater.

After a six-day trial in Plymouth Superior Court, a jury deliberated for eleven hours before finding Michael Robinson, now 47, guilty of one count each of involuntary manslaughter and assault and battery with a dangerous weapon (shod foot). Sentencing is set for January 9, 2026.

The incident occurred around 10:38 p.m. on April 13, 2021, when corrections officers at the facility responded to reports of a disturbance in a bathroom. They discovered the victim, identified as 43-year-old Scott Wonoski of Worcester, unresponsive and bleeding. Despite on-scene medical aid, Wonoski was transported to Good Samaritan Hospital in Brockton, where he was pronounced dead from his injuries. The state Office of the Chief Medical Examiner ruled the death a homicide caused by blunt force trauma to the head and torso.

Officials from the Massachusetts Treatment Center alerted the Massachusetts State Police Detective Unit assigned to the Plymouth County District Attorney’s Office, launching an investigation. Jurors viewed surveillance video from the facility that captured Robinson physically assaulting the victim before leaving the bathroom.

The case was prosecuted by Assistant District Attorneys Kevin O’Leary and Jason Herron, with the investigation conducted by Massachusetts State Police detectives attached to the Plymouth County District Attorney’s Office and the Massachusetts Department of Correction.