I've seen this in action in Amsterdam and was amazed. Rather than charging into the situation guns drawn and yelling police in Amsterdam, seeing that the situation was not dire, first simply made their presence known. They slowly and calmly moved in talking to the perps the whole time. In the end, the situation was peaceably defused.

In America, we are so used to violent interaction with authority that most cannot imagine it working any other way.

One of the first steps we should adopt in the US is the mandatory changing of police uniform color. Green or light blue uniforms are less menacing than the typical US all black uniform. I believe this simple change would reduce police violence.