The game is called "Pick 'Em Out and Knock 'Em Out," according to prosecutors, and it's quick, violent and comes with just a few rules: Select an unsuspecting random victim in public and cold-cock him. Robbery is optional.

That's what three Chicago teens were up to early one morning last week when they recorded a deadly one-punch attack on a 62-year-old man that was posted on Facebook, leading to their arrests on first-degree murder charges, prosecutors said Monday in court.

Delfino Mora, a father of 12, was collecting cans in an alley on the Far North Side when he was struck and fell hard on concrete.

The "Knock 'Em Out" game, while rarely acknowledged by authorities, has surfaced in recent years in news accounts of attacks in Chicago and other Midwest cities. Mora's death also marked the latest in a string of recent Chicago cases in which youthful attackers recorded beatings and put them online.

Prosecutors said the teens spotted Mora about 5 a.m. last Tuesday in a West Rogers Park alley. Malik Jones, 16, announced, "I think I'm gonna knock out this (expletive)," then started the video recorder on his cellphone and handed it to Nicholas Ayala, 17, Assistant State's Attorney Terry Clancy said at a bond hearing. Ayala handed the phone to Anthony Malcolm, 18, prosecutors said.

As the three surrounded Mora, Jones asked him if he had any money in his pockets, Clancy said. When Mora did not respond, Jones punched him in the jaw, she said. Mora fell, hitting the back of his head on the concrete with a loud crack that could be heard on the video, according to Clancy.

Jones moments later rifled $60 from Mora's wallet, prosecutors said.

"All three left the area laughing about victimizing the old man," Clancy said.

About three hours passed before a passer-by found Mora unconscious but breathing. He died the next day of blunt trauma, according to the medical examiner.

The recording of Mora's beating was later put on Jones' Facebook page, according to Clancy. A witness who told police he was assaulted by Jones last month shared the video with others until it was eventually seen by a co-worker of the victim's son, prosecutors said.

Jones was arrested Saturday carrying the same cellphone with the video still on it, Clancy said. All three defendants were ordered held without bond.

Malcolm's family members said outside court Monday that he was a good kid who had never been in serious trouble before and wanted to go into law enforcement.

"He just was at the wrong place with the wrong people," said his sister, Stephanie.

The "Knock 'Em Out" game has been cited in news accounts from St. Louis, Decatur, and Madison, Wis., including several fatal attacks. Last summer, Madison police said they were investigating more than 30 muggings by youths.

"It appears the motive is — in part — money, but some of those arrested have also indicated they see this as entertainment," Madison police said in a news release at the time.

In Chicago, several attacks have gained notoriety after videos surfaced online. Last fall, teenager Scotty Strahan was charged with aggravated battery after someone posted a YouTube video of him punching a homeless man at a CTA train stop while his friends howled with laughter. Strahan pleaded guilty this year and was sentenced to probation.

In January, the video of a beating of a 17-year-old boy in Bridgeport went viral and sparked outrage after it was posted on YouTube. Eight teens are awaiting trial in that case.

Tribune reporter Bridget Doyle contributed.

jmeisner@tribune.com