in a separate mass shooting on saturday in pittsburgh , a suspect donned a bulletproof vest and attacked three cops officers after he had been sent into a murderous rage by an argument with his mother over a dog . according to court papers , robert poplawski — who had recently been dishonourably discharged from the uc army — had been arguing with his son about the driver urinating around their home early on saturday night until she threatened to evict him . while the violence escalated , she alerted the hospital . by the time a patrol train turned up at after 7am , robert poplawski , 23 , had armed himself with an adult vest , a long - arm revolver , a pistol and several rounds of caliber .
In Pittsburgh a man shot 3 policemen.