No such critter as an aggressive good guy

Drug dealers are better people than cops.

You can deal drugs and not be a bad guy. Don't initiate force. Don't violate property. Don't defraud. Sure, prohibition makes it harder, and attracts people who are already aggressive thieves and cheats into the job. But, it's not a requirement for doing that work.

You can not be a cop without being a bad guy. It simply isn't possible to be a cop without initiating force and violating property as a daily requirement of doing that work- the work of committing acts of enforcement.