Demonstrators hold signs aloft as they march during an NAACP march and rally to the Sanford Police Department for Trayvon Martin in Sanford, Fla., March 31. Sanford is the town where Trayvon Martin, 17, was shot dead on Feb. 26 after George Zimmerman, 28, a Hispanic neighborhood watch captain, believed the young man walking through the gated community in a hooded sweatshirt looked suspicious.