A nurse's perspective on the Windsor Mill shooting

Both nurses and police hold the lives of people in their hands. The margin for error is VERY SLIM. When we make mistakes, people die. Yet police are making errors in frightening numbers. How many mistakes is it going to take before things change? It appears to me that nurses are very conscientious about preparing themselves to avoid mistakes, but I’m not sure that police make the same efforts.
If the police woman’s story of grabbing the wrong device is true (which I doubt), then this is a indictment of police training and judgement, and police candidate selection.