I've had run ins with people like this. What worked for me in the past, was speaking sternly to them. Once a place I worked, a homeless guy was running towards

I've had run ins with people like this. What worked for me in the past, was speaking sternly to them. Once a place I worked, a homeless guy was running towards the building with a chair, ready to smash the window with it. I stopped him, just by yelling "no, stop" and then when he asked if I wanted to fight him, I just said "no, but I'm going to call the police if you don't leave." he left. The key is to establish dominance: you are telling them to stop, not asking.