I went to school and worked in downtown Chicago MANY years ago. One of the first things I learned was: You never, ever, ever, ever put money in somebody's hand. They are going drink it, smoke it, snort it,... Or it's a scam.
Had a woman ask for cash to fix her car. White woman, Burberry coat, good shoes. Told her I was going to be late for an appointment, I'd catch her on the way back(both true). She wasn't there. Saw her a couple of days later giving the same spiel to another guy. I walked by a he was pulling out his wallet. As I walked by I said: "Still trying to get that car fixed?" She glared and scurried off.
So by 21 I was an untrusting bastard.