It's all connected. The police unions push back hard against reforms in the prosecutors' office that might subject them to more scrutiny.
https://www.nytimes.com/2020/06/06/us/police-unions-minneapo...
> In St. Louis, when Kim Gardner was elected the top prosecutor four years ago, she set out to rein in the city’s high rate of police violence. But after she proposed a unit within the prosecutor’s office that would independently investigate misconduct, she ran into the powerful local police union.
> The union pressured lawmakers to set aside the proposal, which many supported but then never brought to a vote. Around the same time, a lawyer for the union waged a legal fight to limit the ability of the prosecutor’s office to investigate police misconduct. The following year, a leader of the union said Ms. Gardner should be removed “by force or by choice.”