To be honest, he didn't behave differently from any other street thug caught in camera. We can see on the video how he hunted the little kid, he heard a noise, looked under the SUV and went around to...
I remember when people with mental problems would run naked on the street, or were seeing eating their own excrement in the park. I remember a guy who would walk around in the town where I grow up, his nickname was "gasoline", because he always had a rag with gasoline that he would smell all day...