It’s mayors and county executives that appoint most police chiefs and negotiate collective bargaining agreements with police unions. It’s district attorneys and state’s attorneys that decide whether or not to investigate and ultimately charge those involved in police misconduct. Those are all elected positions.
President Obama, How to Make this Moment the Turning Point for Real Change
What Trump Has Done in His Second Term
An ongoing list (updated monthly) of everything President Trump has done (based on what I could find, anyway).