Shoes. One of the things that I learned over the years, when dealing with the public as an Ambulance officer, and later as an Auxiliary Police constable. Hands, what they look like, and how the person uses them. The running joke with coppers is....How do you stop an Italian guy from talking? Cuff his hands behind his back..... Faces. If somebody can't look me in the eyes, I become curious about why ? Fidgety and unable to stay still ? Drug user ? Smells bad ? Can't stop talking ? Clues my friend, clues.
Of course the ripped and torn clothing from decades ago, is now fashionable with some people. Wearing 2 overcoats in July ? Possible mental illness. Talking to people who are only visible to them ? Same thing. Repeated physical movements such as sitting down and getting up again, over and over ? Clues. JimB.