I've never seen the rules of the so-called "Knockout Game" myself but I'd imagine this would be high on the list:

DON'T show your knockout video to an off-duty cop.

Ignoring this rule was a 27-year-old Houston man named Conrad Barrett, who will appear before a judge on Friday after being arrested last month. According to police, Barrett bragged to an off-duty cop he had just met at a local restaurant about knocking out a 79-year-old black man.

Barrett is said to have asked the cop and a woman he was with if they had heard of the game before taking out his phone and showing the two video of the alleged incident. The cop then found a uniformed officer who arrested Barrett.

In the video, which has not yet been released, Barrett allegedly approaches and greets the elderly man before punching him and yelling "knockout." Barrett is being charged with a hate crime because in further searching Barrett's phone, police found video of him using racial slurs as well as another in which he asks, "That plan is to see if I were to hit a black person, would this be nationally televised?"

The victim, who has yet to be identified publicly, required surgery to repair his jaw, which was broken in two places. Barrett's attorney maintains that his client suffers from bipolar disorder.

Of course, the uncomfortable subtext of this case is that the original fervor over the "Knockout Game" came from white media stoking public fear of young black men. That narrative was obviously bullshit from the start, but Conrad Barrett is anecdotal confirmation nonetheless.