One time this happened to me. But then when they came I used aikido to disarm them whole flipping the gun out of their hands (all of them at the same time). They were so impressed they made me the leader of their primitive tribe and I started collecting resources and completing mini-missions until I became a high enough level to walk through the sewers until I found the final boss and hit the right combo to kill him.
I mean sure but if that doesn't work I have literally taken the el to an industrial district and slept on top of a warehouse, rather than getting picked over by people on the street.
Did you manage to pick up any apples or full-sized rotisserie chickens off the ground to boost your HP? Sometimes they're hidden in trash cans; you have to kick them to find out.
You're a straight up moron if you sleep on the streets of Chicago without a weapon. Here's a hint, get on a rooftop, out of sight.