If police can't correctly identify a threat I don't see how the schizophrenics, racists, people with anger management issues, children, drunks can. Perhaps NOBODY should have use a gun except for the following cases:
- life-threatening situation where someone is advancing with a weapon with intent to kill (domestic arguments, revenge, are NOT life-threatening situations, a lot of Americans don't get that)
- hunting animals
- absolute sobriety

Someone who doesn't have a cell phone to surrender during a robbery is not a threat. A 13-year-old girl emerging from a LINK train with a 21-year-old woman is not a threat. A youth with his hands up 35 feet away from a squad vehicle is not a threat. An unarmed high school student minding her own business is not a threat. A drunk unarmed 19-year-old seeking help after an auto accident is not a threat.

Americans will simply have to work on their reasoning and verbal defense skills, common sense and their compassion. Doing so will not compromise their freedoms. Take it from the civilized world.

Don't blame trigger happy cops. Blame a society where guns have become the first line of defense for all altercations. We are no longer taught to fight responsibly as children. All violence is bad. So we grow up to be defenseless adults. Yet from childhood we are taught that guns are our birth right as Americans. So without any other form of self defense deemed exceptable, we are left with guns; the most violent way to settle a dispute, or defend ones self.
American cops are american people. So it stands to reason that an American cop will do what any american will do, think to grab a gun at the first prickles of trouble/danger/fear.
If you want to stop gun violence, teach your children to throw a punch. And don't punish them if they win a fight. Gun violence by cops, and people in general, will go down in a generation.