In the story I'm writing one of the characters is a drug dealer. She and her friends treat this is quite a blase way, as if it does not matter to them morally and she is just about to get arrested by someone who knows it does matter a lot.

At the moment this person is an Auror. However would the Aurors be interested in illegal substances (as a crime not for their own use obviously)?

If the Aurors were not in charge than who would be?

Would it be conceivable that, whilst not in charge, they act as the 'muscle' as it were and do the arresting?

Any help/ thoughts greatly appreciated?