[triceratops]

> one isolated example

Is it though?

Who defeated the first iteration of the KKK? It wasn't local sheriffs, it was the feds.

Who brought charges against Ahmaud Arbery's killers? The local PD cleared those lynchers. It needed the Georgia state authorities' involvement.

Local police authorities can be of highly variable quality, and they don't have as much oversight as the higher levels of law enforcement. I'm not inclined to trust in them more just because they're "local". Their closeness often leads to massive conflicts of interest. Trust has to be earned.