I had a large belligerent street bum approach me in an ally I was walking through in Detroit for work. It was daytime but on Saturday morning when this part of downtown D is no longer hopping with office workers. He was almost shouting that he was a vet and needed some money. I was backing up saying sorry I had none but he continued at a quick pace towards me. Walking backwards facing him I came up to a concrete like structure by the alley and proceeded to lift my shirt up to access the grip of my sp101 just in case. At that exact moment he turned and walked off the other direction.