Is it better to be safe than sorry?

One of my employees calls me and tells me that she locked to doors to the store because a guy pulled into the vacant parking lot, stands in front of the store in all black clothes with a black bag draped across his shoulder. He began to take pictures (with his phone in his extremely shaky hands) of the parking lot and our front door. He then paces back and forth in front of our store smoking a cigarette. Chelsey locks the door, keep in mind usually weekend shifts, only one girl works. The guy then begins to pull on the door and bang on the windows. So Chelsey calls me and asks what to do, I tell her to immediately call the police just to inform them and have a patrol officer come to the shopping center. I also tell her I will be there soon so I go right over. In discussion with my boyfriend on the way home from the store, is it better to stereotype this guy and be safe or is it overreacting that we automatically assume he's trying to do something fishy in front of our store?