An innocent woman was killed in her home in my city not too long ago because her neighbor called in a welfare check because she left the front door open during a nice evening.
Not too long before that a cop from a city adjacent to mine mistook a mans apartment for her own and murdered him.
Cops needlessly killing innocent people isn't exactly a rare story nowadays. I can understand the distrust even if statistically it's low things will go poorly.
That being said, even if the cops are incompetent, the law is still important and those who attack others due to their race or identity need to be in cuffs and go through court. Not calling the cops will make sure your attackers get away and never face justice.