I see some rather extreme responses here and I am pretty radical too but don't let this shit replace your common sense judgement when dealing with people on personal level.

Use common sense.

Being a cop doesnt make you an asshole. Nazis were friendly with each other and many even had jewish and foreigner friends. The job is whats the problem and unfortunately its part of a persons identity. Every person has subjectively good and bad sides, you have to decide how heavily each weighs

Is this person a new friend? Or is this person a cop. Getting to know someone and becoming friends with that person is a relationship. Deciding this person is horrid because they are a cop is superficial. And that person will never be your friend, there is no relationship there. Is this person a Human you want to get to know, or a job title you hate.

One of my friends is a veteran. I be sure to tell him my thoughts on his deployment in Afghanistan and I've told him multiple times he deserves his PTSD.

But I still love that man as a human and a friend. We get along together, we laugh, I call him a terrible person, and life continues.

Basically, don't change your beliefs based on who you're with, and it's fine to be friends with a cop. I have other friends who are terrible human beings as well, but they make up for it with other great qualities. If anything, being friends with a PoS is the best way to make them a better person; you really have an opportunity to help society.