Someone keeps sleeping in my car, window was broken a while ago so I can't lock it... how do I curtail without the police

Sooo... I live in Philly, not the best area... and there is a homeless person, it could be a man or a woman, I can't tell... def a crackhead, that has been sleeping and smoking crack in my car for the past week. I've kicked her out multiple times this week, but because I am running a business right here I can't make too much of a scene or be too aggressive for fear of eternal retaliation on my business.

I am lucky to have the customers I have... I don't want to lose them because of this.

This homeless person is an african american female(I think) with the "why so serious" batman knife marks on her cheeks, and is always wearing loose-fitting clothing, which makes it hard to assess whether or not she is armed. I threaten her with calling the police and she usually sulks off without saying much. I need to bring this to an end without calling the cops... I've seen too many examples of citizens resorting to the authorities only to end up being shot or tazed. Fuck that, is there anything I can do to avoid involving those assholes?