MassLive.com reports the dog broke through a barrier in a window and launched at the dogs near Lincoln Grove Park Saturday night.
Police said the owner of the two dogs began to yell and tried to shield his animals, but the dog continued to attack and bite both dogs.
Chicopee Police Officer Michael Wilk said “as a last resort,” the man removed a pocket knife and stabbed the canine. The dog then ran away and was found dead by officers nearby.
The man tells police he was also concerned for his own safety. Officials closed the investigation, saying the man was protecting his dogs and himself.