The most important unexamined question is whether police are trained to use force immediately as a first resort before they assess a situation or determine if they are at the correct address. Are the police trained that the lives of police officers are so much more valuable than the lives of possible suspects, or a houseful of people into whose residence a heavily armed SWAT team enters, that police officers must not accept the risk of judicious behavior when encountering citizens? If this is the case as all evidence indicates that it is, then the police when they gratuitously murder members of the public are merely doing what they have been trained to do. As police are trained to use violence as a first resort, the police cannot be held accountable when they do.
There are a large number of videos available online that show that the first thing that police do when they arrive is to use force.
No sooner is Michael Brown in the grave than Cleveland cops kill a 12-year old boy who has a toy gun that shoots plastic pellets. The child is threatening no one–indeed there is no one else present. The boy seems to be playing a fantasy game in his head. A busy body calls the police. The police arrive and instantly shoot the kid down.