in a separate mass execution on saturday in pittsburgh , a man donned a bulletproof vest and killed three cop officers after he had been driven into a killing fury by an argument with his mother over a gun . pursuant to court papers , mr poplawski — who had recently been dishonourably suspended from the us marines — had been angry with his mom about the dog urinating inside their home immediately on the morning when she threatened to oust him . when the argument ensued , she told the cops . by the moment a patrol vehicle turned up at after 7am , mr poplawski , 23 , had armament himself with an assault rifle , a long - arm pistol , a pistol and several rounds of ammunition .
In Pittsburgh a man shot 3 policemen.