Reverend Al Sharpton holds the microphone for singer Chaka Khan as demonstrators protest the shooting death of teenager Trayvon Martin during a rally in Miami, Florida April 1, 2012. Attorneys for the family of slain black teenager Trayvon Martin are asking the U.S. Justice Department to review reports that prosecutors undermined a police investigation of shooter George Zimmerman by overruling a detective who wanted to charge him. REUTERS/Ed Linsmier (UNITED STATES – Tags: CRIME LAW CIVIL UNREST)