Minority culture(and increasingly in majority culture as well) is steeped in crime with a 'snitches get stitches' attitude. If they want to stop the violence then they need to be willing to send the perpetrators to jail by working with police. It's almost a guarantee that the people in those neighborhoods know who the fucking assholes are but due to some notion of 'loyalty' aren't turning in the shit stains.
Thats this anon's two cents anyway.