The organ started playing the recessional as the congregation - mostly families with girls and boys dressed in white dresses and suits - got ready to pour into the sunlit streets outside the church, at 28th Street and River Avenue.
Meanwhile, the ushers and Koenig, who had recently had open heart surgery to repair an aortic valve and was back to work on a limited schedule, started the two-minute walk from the church to the rectory, where they planned to put the bag, containing about $500, in a safe.
A minute into their walk, a man dressed in black, holding a hood to cover his face, walked toward them, lifted an arm to point the gun, grabbed the satchel, and fled.
"He didn't say a word," Koenig said Monday. "No one did."
What happened next was heroic and stupid, the Rev. William "Jud" Weiksnar, also of St. Anthony's, said afterward.
Maybe it was the frustration of living in a city so accustomed to crime, or the juxtaposition of the innocence of the church service with the aggressive act, but Garcia and Torres darted after the man.
They chased him a few blocks, to an intersection where another parishioner who had witnessed the robbery tried to block the escape path with his SUV. The robber turned the gun toward the SUV, and the man swerved, Koenig said.
Koenig said that the weapon looked like a BB gun but that he was still terrified he would hear gunshots as he watched the ushers run after the man, as he gripped the key to the rectory in his habit pocket.
Moments later, as the robber tried to scale a fence to get away, he dropped the bag and kept running.
"I would have preferred they just hand the money over and let him go. It's not worth the risk. It was a brave thing, very heroic, but not very practical," Koenig said.
Weiksnar saw the commotion from the church steps, where he was being photographed with the children, who were posing with hands folded after celebrating First Communion.
It's not the first time something like this has happened at the parish, staffed by Franciscans. In the 1980s a robber hit a friar over the head and snatched the collection he was transporting. That's when the church instituted the policy of having two ushers accompany the friar on the trip.
Police responded within minutes, Koenig said, and Monday evening arrested a suspect. They say they will now assign police to the church perimeter on Sunday mornings.
Weiksnar said he hopes the robber gets help.
"If somebody's going to steal money from a church, they're probably very desperate. That's the impressive thing, the guys chasing him were saying, 'We have to pray for this guy, he's probably in a very bad situation.' "
Koenig said he hopes the robbery does not set back the church, which had its largest attendance of the year for the morning of communion Masses, or discourage the community, which has advocated increased safety measures, including lights in neighboring Von Neida Park.
"It'll scare a lot of people. That's the problem," Koenig said. "Here we have another violence problem in Camden, and we were hoping we were getting further away from that."