His parting shot: "Unarmed!"
Across the street, questions about the case were met with a different selection of facts.
People at the Wilson rally brought up the arrest record of Dorian Johnson, the first witness, who said Brown was shot in the back (autopsies indicate the bullets hit him from the front) and with his hands up.
They were quick to mention two unverified accounts that provided support for those who argue Brown rushed toward the officer.
No mention was made of the other three witnesses — Tiffany Mitchell, Piaget Crenshaw and James McKnight — who also said they saw Brown's hands up. None of those witnesses described Brown rushing toward the officer.
Wilson's supporters mentioned that Brown stole a box of cigars from a store and roughly shoved the clerk minutes before he encountered Wilson.
"That'd say something about your character, right? And then you might start a fight with a cop?" said a plumber who gave his name as James Edwards.
Edwards mentioned a report, based on anonymous sources, that Wilson's orbital eye socket was fractured. But what about another anonymously sourced report that there was no fracture?
"I don't know if it's true or not. It makes no difference. He had facial wounds when he was hit. He was 100 percent right to shoot," Edwards said, as a passing driver honked in solidarity.
Stephens, one of many people wearing the Wilson badge T-shirts selling for $20, said that if Brown grabbed Wilson's weapon and assaulted him, "that gives him every right to shoot him."
At first Stephens said he could see a gray area in the case because there was so much unconfirmed information circulating. Then he said, "If we assume this officer's account is accurate, there is no gray area in the state of Missouri," meaning he believed what Wilson did was legal under state law.
Did he assume Wilson's account was accurate?
"Yeah, I do," Stephens said.
Several witnesses described Brown breaking away from Wilson and running away. They recalled the officer firing shots at the fleeing Brown, and then Brown stopping.
The crucial question is what happened next.
The rallying cry of "Hands Up, Don't Shoot" has become a powerful symbol of Brown's death. But could "Hands Up" be more myth than fact?
Alternatively, could Wilson, facing possible criminal charges over his decision to shoot, have exaggerated Brown's aggression, shading his statement of facts about what happened?
With so much incomplete and sometimes conflicting information, some confirmation bias is bound to occur.