What to do about a squatter?

Hey just moved onto a new block in Philadelphia. All the neighbors have warned us about the squatter down the street. So nobody on the street likes him already. He sits on a chair in front of the house seriously 24/7. He knows when people leave the house and enter the house. It's kind of scary. To top it off he bums things like water, cigs, and anything else he can get his hands on. He also sell's pcp and other drugs. That's probably why he is able to stay up 24/7. Iv'e lived in this kind of hood before but never had to deal with a squatter. Any advice on getting him off of my block?