Are all cops corrupt? Or are there good and bad police?

The few ba ones make the otherslook bad too, just like everything else.
Reminds me of a joke though

Guy gets pulled over fro speeding, cop gets out and ask him why he going soo fast. Guy replies that he’s on his way to work. Cops asks what he does for a living. Guy responds “I’m a rectum stretcher” Cop says what the heck is a rectum stretcher. The guy says" i take rectums and stick two finers and and start to stretch them out, then 3 fingers, and then the whole hand and i keep doing this till it’s 72" long " Cops says “What the hell do you do with a 6 foot asshole?” Guys says “give him a gun and a badge”