Local Law Enforcement.
I agree that the local police are _usually_ less corrupt than broader agencies (Your mileage may vary if you live in a minority-resident/majority owned area). That said, the biggest LE news in a couple decades in my home town was when a couple local cops were caught tipping a burglary ring off when asked to "keep an eye on our house, we're going to be traveling for a week".
Biting the hand that feeds IT
