Attorneys for a Florida neighborhood watch volunteer who fatally shot an unarmed black teen have withdrawn as his counsel, saying they have lost contact with him.

Attorney Craig Sonner said Tuesday in a news conference they haven't heard from George Zimmerman since Sunday. They said that against their advice, Zimmerman contacted the special prosecutor who will decide if he should face charges.

Zimmerman is at the center of an investigation over the shooting of Trayvon Martin, 17. Zimmerman says he shot Martin in self-defense after following him in a gated community in Sanford on Feb. 26.

Martin, who was unarmed, was black. Zimmerman's father is white and his mother is Hispanic. The lack of an arrest has inspired nationwide protests and some claims of racial profiling, which Zimmerman's supporters deny.