To be fair aurors seem to be doing the job of detectives/cops/militia/commanding officers/military police/federal agents/CIs/Deputies/Marshals/Troopers/ Dementor management/whatever
It's not just a cop. Besides the guys seem to be paid decently enough and deal with the most nastiest of the nastiest shit in the magical world. It's a miracle people decide to do it, given the mortality rates it seems to have and the kind of bullshit they need to deal with