A kid is doing a tour of a police station.

When they get to the officers' locker room he asks :

"Only police officers have access to this room, right? "

"Yes" answers the tour guide.

"So why are there locks on the lockers?" replies the kid.

Let me guess, this is not their fault because:

A) They investigated him and found nothing wrong.

B) They just aren't very good at investigating and come on! It's hard work!

C) The police union and department is a corrupt get out of jail free card for any aspiring criminal and its well tolerated institutionally, unless you really embarrass yourself with egregiously public criminality that you are finally, reluctantly, put on political trial to face actual consequences.