Belchertown Man Charged With Murdering Wife Inside 55-Plus Community Home

Mark Opper allegedly shot his wife Diane Opper inside their home at 111 Daniel Shays Highway on the afternoon of March 27, 2026, then was held without bail three days later after a murder arraignment in Eastern Hampshire District Court. Both were 56 years old. Their residence sits inside Summer Hill Estates, an age-restricted community built for adults 55 and older in Belchertown, Massachusetts.

Belchertown Police Officers Draine Colon-Rivera, Cameron Woodward, and Michael Jablonski responded to the address at approximately 5:10 p.m. and found Diane Opper on the floor with multiple gunshot wounds to her torso. A firearm and bullet casings were recovered approximately ten feet from her body. She was transported to a hospital and pronounced dead.

Judge Bruce Melikian presided over the March 30 arraignment, where Opper pleaded not guilty to charges of murder and assault and battery on a family or household member. The judge ordered him held without bail. Court-appointed attorney Jonah Goldsmith represents the defense.

The case is being prosecuted by Assistant District Attorney Erin Aiello, who serves as Chief of the Northwestern DA's Domestic Violence and Sexual Assault Unit. District Attorney David E. Sullivan, the elected Northwestern DA since 2011, created that unit and has maintained a policy of prioritizing prosecutions involving high-risk domestic violence offenders. Sullivan's office covers Hampshire and Franklin counties as well as the town of Athol. Assigning his unit's chief prosecutor to handle the case reflects how the office has categorized the alleged killing.

The Massachusetts State Police Detective Unit assigned to the Northwestern DA's Office is conducting the investigation alongside Belchertown Police. Physical evidence from the scene, specifically the firearm and casings found approximately ten feet from Diane Opper's body, is expected to anchor the prosecution's account of what happened that Friday afternoon. The next scheduled court date is April 27, 2026.