Tashawn Bernard, 12, was detained by Lansing police officers while he was taking out the garbage in a video clip that has drawn criticism on social media.
I mean, I mostly just wanted to humorously dunk on cops, but if you want an actual argument:
Cops have an entire TV genre dedicated to propaganda in their favor, which can lead otherwise decent people to believe that they aren't that bad and join up.
So, it's possible for a person to be both a decent person and a cop… but not for long. It can't last since they soon either stop being decent, stop being cops, or have "accidents". But can good cops exist? Yes, if only for a short.
(And I'm intentionally using "decent/good person" rather than "not a criminal" because what's criminal and what's immoral are two separate things. Cops can use asset forfeiture as essentially a form of highway robbery, but doing so is technically not illegal, and thus not criminal.)