The internship is a bad idea. If they are selling crack, you can't match what they earn. Invite a military recruiter to talk to them.
I don't know if it is possible, but dogs scare criminals more than cameras do. Believe it or not, criminals can spot fake cameras. That or the criminals are too stupid to notice them. Obviously, they aren't working. And your money would be better spent buying the police lunch rather than the punks.
Another thing to do is shake them down. Get someone to flash a fake badge and take their money and crack. (Sounds good in theory, don't really try this or things would escalate to violence quickly)