Al Sharpton and Martin Luther King III joined Martin's parents at the rally.
One sentiment was clear among the thousands who rallied Thursday night for action in last month's fatal shooting of an unarmed Florida teenager: justice.
"We cannot allow a precedent when a man can just kill one of us ... and then walk out with the murder weapon," Sharpton said, flanked by Martin's parents and a stage full of supporters. "We don't want good enough. We want George Zimmerman in court with handcuffs behind his back."
The rally came the same day that bitterly criticized Police Chief Bill Lee stepped down temporarily, he said to help quell the rising passions surrounding the case. Hours later, Gov. Rick Scott announced that the county prosecutor also had recused himself from the case and that a state attorney from Jacksonville would take over the investigation.
Sharpton attended the rally just hours after the death of his mother. "This is where she would want me to be," he said.