I was recently the recipient of a carefully prepared right hook from a fearesome-looking (white) contribution to society, less than half my age, who was trying (unsuccessfully) to rob our Post Office. It sent me sprawling across the room, but I remained able to fight him off long enough for the alarm to be raised. I still can't work out why I wasn't left unconscious..I didn't even have a mark. I wondered if he was doing something wrong.
By the way, he was identified by fingerprints, CCTV, witnesses, and admitting the whole thing to others. Shortly after the event the police were given his name and address. What did he get? Nothing. Welcome to the UK.