Public records and databases available to citizens is a potential control against these folks getting hired again in positions of power and trust in the future (positions that warrant a greater level of accountability, imho). It is a form of append only public distributed trust ledger. Correlate such datasets against your local law enforcement staffing continually if their hiring criteria is suboptimal, using a combination of FOIA/FOIL requests and on the ground activism/investigative journalism.

The IJ Database of ALPR Abuse - https://ij.org/the-ij-database-of-alpr-abuse/ (181 incidents documented, as of this comment)