FWIW, here is some additional info I didn't see in the linked article. After the dad got the thief out of the car he fled. The "mob" didn't get involved until after that:
"There was an initial altercation between Mr. Hood and the father of the children and that was the time that he was removed from the vehicle at 29th and York Street. However, I don't want to speculate as to whether the father’s involvement continued after that point," Smith said.
Chief Inspector Scott Small said Hood then tried to run away and again the boyfriend was able to catch up, this time a half-block away, leading to a fight.
"Then other males from the neighborhood intervened and began punching and kicking the male who took the vehicle," Samll said, "to the point where he was rendered unconscious."
"The crowd kicked and punched Mr. Hood until the arrival of responding police,” Smith added. “At some point Mr. Hood became unresponsive."