A police officer is murdered every week on average. I imagine the numbers for those shot at is much higher, since most gunshot wounds don't result in death and most shots probably don't result in hits.
This crime is in many ways the result of the violence of the police which means other citizens are afraid to call and cooperate with the police. Exactly what you need to reduce this crime.
Similar stuff happened in Iraq. When civilians could not trust the American occupying force then militias and terrorists filled the power vacuum.