For number 1, I would look for scenarios where rhe officer was found to have committed misconduct or found to be unreliable. Then watch if they're involved in subsequent cases/departments when should probably never work as an officer again. Just my thoughts on one thing that could be done.
Uhh like how many murder cases got solved, how many drunk drivers had their driving licenses revoked, how many speeding tickets went through, how many stolen cars and goods found its original owner, how many pickpocket thieves, shoplifters, bulglar cases got investigated, you know ... Stuff police exist for?
Those stats are typically at the department level. They don't necessarily match the court records either (eg the police may mark a murder case as solved even if the prosecutor thinks the case is too weak and never goes to court).
