in a subsequent mass shooting on saturday in pittsburgh , a man wearing a plexiglas vest and kill three police officers after he had been drive into a murderous rage by an dispute with his mother over a dog . according to court papers , richard poplawski — 25 had already been dishonourably issued from the us navy — had been arguing with his mothers about the person urination about their garage early on weekday morning where she threatening to expel him . while the arguing escalated , she called the police . by the times a policeman car turned up at after 7am , mr poplawski , 23 , had armed himself with an army rifles , a right - action shotgun , a pistol and several shells of ammunition .
In Pittsburgh a man shot 3 policemen.