The commission wrote to Chief Alfonso Morales asking for the audit and all body-camera video of the arrest. Commissioners want the findings to be turned over to them and the Milwaukee Common Council.
Police officers confronted Brown in January after he had parked illegally in a drugstore parking lot. Police video of the arrest shows officers swarming Brown and taking him down when he didn't immediately take his hands out of his pockets as ordered.
Three officers involved in the arrest have been disciplined, with suspensions ranging from two to 15 days.
Brown's attorney Mark Thomsen said he has delayed plans to file a federal lawsuit Friday and likely would file it next week.