The police departments and individual officers are held accountable for illegal conduct only very rarely. Only when we change this will the end result change. My city has a similar problem and all they did was raise the taxes for the police last year.
An idea I think that has merit is individual malpractice insurance like in the medical field. If an officer becomes too costly to insure because of illegal misconduct, no department will hire him.
RE: Paying Out Hundreds of Millions Over Police Misconduct