I used to travel on Greyhound a lot.
I never met a violent homeless person in the USA.
I encountered a raving Arab in Paris, France who I might reasonably assume was a street person, but he didn’t physically hurt anybody.
I suspect drugs are involved when it comes to violent homeless incidents. People are handing out too much money to panhandlers. At $1/handout, after three handouts a guy can get a hamburger at McDonald’s.
Where does a homeless person get a gun? Last week a “homeless” man killed two in a library, in Tulsa, OK.