The shooting happened outside St. Columbanus Church, near 71st and Prairie in Chicago's Park Manor neighborhood.
Another man was critically wounded and taken to Stroger Hospital.
Witnesses say they believe one or possibly two gunmen stalked their victims during the funeral for another man inside the church.
Monday night, the steps of St. Columbanus were part of a crime scene. At least 20 yellow markers indicate shell casings, a sign of the major gunfight that took place as a crowd of hundreds was leaving the funeral for 32-year-old James Holman.
Deborah Echols Moore was inside the church.
"You didn't know which way to go or what to do," Moore said. "All I knew to do was run for my life."
Witnesses say the gunmen were apparently targeting their victims.
Mary Sistrunk's son Sherman Miller was killed.
"That's what it's all about, all this gang stuff," said Sistrunk. "That's what it's about."
Pastor Corey Brooks had just finished giving the eulogy and was leaving the church when the gunfire erupted.
Brooks' message was about peace and bringing an end to the violence.
"I've seen a lot of things in my life, but this has probably been the toughest and the most heart wrenching," Brooks said.
"Here's the family grieving the loss of their loved one and then gunfire erupts at the funeral, in the church, at the church, just despicable," said witness Charles Childs.
"Too many young people are dying," said Tyeshia Duckett, an aunt of the victim. "This is her second child. Please, stop the killing."
Sherman Miller's mother Sistrunk says her son knew he was in danger and he wanted to leave town.
"He had just talked to me this morning," said Sistrunk. "He said, 'Mama, they're gonna kill me.' I said, 'They're gonna kill you where you lay your head? You need to leave from there and get God in your life.'"
The second victim who was critically injured has a bullet lodged in his spine, according to Pastor Brooks.