"Violence isn't the answer," she said. "If violence is the first thing that you think about when there's a problem, think again."
Carlee McKinney, 12, said he stopped playing outside after the deaths of Hadiya and Jonylah because he was scared. His fears have ebbed somewhat recently, but he still prefers to stay inside with the doors locked.
"I want it to get better, so maybe being in this march will help," he said.
The march ended just as police scheduled a news conference to announce Willis' arrest. Reed-Scott saw the criminal charges as an affirmation of the rally's purpose.
"It's amazing to have (Willis) arrested on the day that we stand up for peace," she said. "It shows that the universe wants the violence to end."
Tribune reporters Carlos Sadovi, Jennifer Delgado and Stacy St. Clair contributed.