It was in July 2012 that prosecutors say Anthony Malcolm and two other teens, Malik Jones and Nicholas Ayala, were playing a game called "Pick 'Em Out, Knock 'Em Out."
They say the trio encountered Mora, who happened to be collecting soda cans in a West Rogers Park alley, as they played the game.
The suspects attacked Mora, who cracked his skull and died a day later of a brain injury.
One of the other defendants is accused of delivering a deadly blow to Mora while Malcolm recorded the attack on a cellphone. The video was later posted on Facebook. During the verdict, the judge explained why Malcolm was guilty as an accomplice.
"The fact that he did not do anything during the crime to stop it and did not report it anonymously even to the police," said Risa Lanier, Assistant State's Attorney, at the Leighton Criminal Courthouse.
Mora was a husband and father of 12 children. He supported his family partly by collecting aluminum cans. Six of his children were in court for the verdict Monday. They say they are pleased with the judge's decision.
"We feel a little bit of peace in our heart because the judge made the right decision. But on the other side, we feel a little down because this decision is not gong to bring our father back. . . He was the head of the family. Now we have to keep that in our heads whatever he did in this world, keep it with us," said Emmanuel Mora, son.
The family says the past year has been difficult and they are trying to put the tragedy behind them.