 ABC's Mary Bruce. In a park about a mile away from the convention hall, five Columbus, Ohio police officers working security for the convention shot and killed a Milwaukee man brandishing two knives in a fight with another man and ignored repeated commands to stop. Columbus Police Union boss Brian Steele. Our officers are trained to recognize a threat. They're trained to stop the threat. We're trained to de-escalate if we can. We're trained to use a taser if we can.