Evicting someone for drugs is difficult. If you call the police, chances are that they will do NOTHING! Even if they set up a stakeout and arrest the guy, in the United States he will be presumed innocent until proven guilty. A guilty verdict could take months. Without a guilty verdict, the drug dealer is going to spew some of the usual lies in court and you will be VERY LUCKY if the judge evicts him (and it will cost you a bundle to go to court and have the eviction denied). What I'm trying to say is that evicting someone for something other than non-payment of rent is very difficult.
What I do is try to get the druggie NOT to pay rent. I AM NOT RECOMMENDING THIS TO YOU, but here's what I do. I wait until rent day, then I tell the druggie that I know that they've been selling drugs. I tell them that I have called the police and the drug task force; that I have neighbors taking pictures of their illegal activities; that I will do everything I can do to have them arrested; and that I will be evicting them! Then, I demand the rent.
They will be quite angry and refuse to pay the rent AND I'VE GOT THEM! Evicting for non-payment is easy. I've done this a bunch of times and it has worked every time. The only little problem is that drug dealers can be dangerous and you need to exercise caution and take precautions. Again, I'm not recommending this, but that is how I do it.
Regardless of what you do, you run the risk that your property will be damaged. Having a bunch of druggies constantly in your house smoking crack causes a lot of damage. An angry drug dealer can cause a lot of intentional damage (although I haven't had that happen very often). A drug raid causes a lot of damage. Having a drug dealer in your property is almost always a loser for the landlord.
Mike