It actually wouldn’t be all that hard to change the system to make it work in a less corrupt manner.
1. Audit officer actions by having a team of authorized auditors who act out the commitment of a crime with or without guns involved(without the officers knowing this is only an audit and not an actual crime)and then review the findings of the officers versus what actually happened. Ensure that the audit includes things like a "beautiful young woman, minorities, elderly" and any other situation that might show inappropriate police activity or inappropriate reporting of a crime.
Retrain those who only make simple human errors and fire those who are grossly wrong or do intentional wrongs. The human factor and judgment need to have reasonable room but the scenarios should be pretty straight forward.. Possibly include video of the "incident" so officers at the time of the investigation can see what happened and see if they still report it inaccurately. Record the investigations of the officers on secreted cameras so each part of the audit can be used as a training tool.
2. All police cars should be equipped with GPS that reports to a central office so that police who are intentionally speeding and not responding get ticketed like anyone else.
Audit officers in a random manner with differing people.
3. Courts could be held to a higher standard also by having a judicial review board of non judicial system individuals (disinterested parties) who can review complaints of outrageous non enforcement of court orders by courts or orders in complete violation of logic and evidence. Give the board the power to punish and dismiss judges in cases of gross abuse of power or outright failure to enforce the law.
Courts could and should be audited in a similar manner to police to ensure that at least a reasonable outcome is obtained.