Okay, this campaign is gonna be a dark and sinister urban adventure, so law enforcement is corrupt and doing evil things.
Okay, this is a swashbuckling tale, a la Robin Hood against the Sheriff of Nottingham, so law enforcement is corrupt and doing evil things.
Okay, this is basically a noir detective style adventure, so law enforcement is corrupt and doing evil things.
Okay, I noticed I keep making law enforcement evil, so I'm gonna do a one shot set in hell. There's no civilisation or human NPCs, so law enforcement isn't even here. The year is 1312...