MILWAUKEE — About 500 people have rallied in downtown Milwaukee to protest the outcome of the Trayvon Martin shooting case.

The Milwaukee Journal Sentinel reports ( ) that a series of speakers outside the Federal Court building Saturday, including politicians and religious leaders, called on the U.S Department of Justice to file civil rights charges against George Zimmerman in the death of Martin.

The Rev. Al Sharpton's National Action Network organized "Justice for Trayvon" rallies and vigils outside federal buildings in over 100 cities Saturday.

A Florida jury acquitted Zimmerman of all charges in the March 2012 shooting of the 17-year-old Martin, who was unarmed. The former neighborhood watch leader claimed self defense, while others contend Martin was targeted because he was black.