[Update] Grove Street Murders a 'Family Dispute'

Just after noon, small pockets of residents continue to come to Belmont's Grove Street Playground to watch the house across in Cambridge at 161 Grove St. 

Two trucks with only the red number 24 and a phone number on its side stand in the driveway. Every now and then, the front door would open and one or two men  – wearing masks, gloves and protective booties – would place material into a cardboard with a hazardous waste symbol on the flaps, later removing the box into the back of the trucks.

Along the street, unmarked police vehicles sit parked along the street as law enforcement from the Cambridge Police and the Middlesex District Attorneys Office continue their investigation of the brutal murder of three adults yesterday, Friday, Dec. 9, inside the house of the killer who was found dead by his own hand hours later.

According to a press release from the Middlesex District Attorney’s Office, at approximately 6:40 p.m., Cambridge Police responded to a call for shots fired inside the single family home across the street from one of Belmont's most popular playgrounds, known as the home of Belmont Youth Baseball, basketball games and a small hill used by many parents and children use for sledding after it snows.

Upon arriving, officers found three family members who had been fatally shot. Identification of the deceased is not being released at this time pending notification of the next of kin, according to the DA's office.

The alleged suspect, John “Jack” Brosnahan, 67, who was a former Bedford Police Officer and resided at the residence on Grove Street, was found dead around 10:30 p.m. at 1400 Soldiers Field Road in Brighton from an apparent self-inflicted gunshot wound. 

The DA said that at this time, it was believed Brosnahan shot and killed the three victims, and then shot himself. 

The investigation, including the circumstances of the murders, remains ongoing, said the DA.