I read the article posted by Seattle Tiger, sound to me that this guy was at least doped up, said he got hit by a car, went down and then started chasing the car. The article says he was a muscular guy.
I work day shift now, there are alot of "old timers" on the shift. Occassionally one gets beat up so bad he retires. I was with one not long ago and we battled a guy young enough to be my kid. The older cop I was with tore a rotator cuff and injured his hip. He had surgery on the rotator cuff and is now waiting to have hip surgery. He retired not long afterward. He was lucky I was with him, this kid was drugged up and might have killed him.