And even if Omar was in a gang, Kozy knew him as a good young man.
"If I called him and said, 'Omar, we need to move this pile of crap from here to here,'" Kozy said, gesturing around the center, tears in his eyes, "he'd come."
Years ago, when Kozy signed on as the church's youth minister, McKinley Park was on the cusp of change. The immigrant groups who had settled the area were moving out. New immigrants were moving in.
Kozy stayed. He worked for a while at Kozy's Cyclery, the popular Chicago bike shop founded by his father, but more and more he was drawn to the youth ministry at the church where he'd been baptized, across the street from the house where he grew up.
The job eventually became full time, and as the neighborhood evolved, so did his work. It was less about taking kids on recreational jaunts, more about keeping them in school, protecting them from violence.
He remembers the first of his kids to be killed.
"I still have his holy card," he said. He walked to his office, fetched a small memorial card.
A boy named Michael. 1974-2000.
Last week, Kozy went to a CAPS community policing meeting. He stood and spoke about Omar, wondering where the outrage was. His neighbors, he fears, have learned to live with the violence. His kids too.
That's why he thought about putting the photo of Omar's body on display.
"I wanted the kids to see the connection," he said, "that any group that promotes violence is going to lead to laying in the street, dead."
I asked Kozy if Omar's death had temporarily knocked the wind out of him.
Sitting at an old desk in the teen center, he looked down and began to fish through his briefcase, as if to hide his tears.
"Not temporarily," he said.
Then he recovered. If only the center could get more money, he said, to hire more help — grants have dried up, the budget has been cut — maybe they could accomplish more.
"You have to have faith that what you do actually works," he said.
Does he have that faith?
"Yes," he said. "Yes, I do."
And after someone at the CAPS meeting last week mentioned that a 14-year-old boy, one of the center's kids, had recently joined a gang, he went to the boy's house.
Maybe this one could be saved.