An attorney representing Crawford's family says Wal-Mart surveillance video of the shooting shows it was unjustified. Crawford is black, while the two officers involved are white.
Signs and chants at the rally urged, "Release the tape." Organizers said the Rev. Al Sharpton plans to come to the area in a few weeks to speak about the shooting.
A special grand jury will meet Sept. 22 to consider charges in the case. Ohio Attorney General Mike DeWine said releasing the surveillance video could raise issues of a tainted jury pool if the case results in a trial.
"I think that it is playing with dynamite, frankly, to release that tape at this point," DeWine told the Dayton Daily News. "And I think the dynamite simply is that it blows up and you can't get a fair trial. That's what we worry about."
Crawford's parents want a federal investigation and have met with U.S. Attorney Carter Stewart. Family attorney Michael Wright said Stewart assured them Thursday that the Justice Department is monitoring and assisting Ohio's investigation and will independently determine the merits of any potential federal prosecution.
A spokesman confirmed that federal authorities are monitoring the situation.
Another rally is planned Sunday outside the Wal-Mart by people who say they want to show their support for police.
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