George Zimmerman's business with the criminal court in Florida may be done, but a federal civil rights investigation remains open, and legal experts say he could face a civil suit.

A federal investigation into the shooting death of 17-year-old Trayvon Martin is underway, and prosecutors from the Justice Department's civil rights division will review evidence from the FBI and the Florida criminal trial, the Justice Department said Sunday in a written statement.

Zimmerman, a neighborhood watch volunteer in a gated townhouse community in Sanford, Fla., shot and killed Trayvon on Feb. 26, 2012, as he returned home from buying snacks at a convenience store. Zimmerman, who is Hispanic, claimed he shot the unarmed African-American teenager in self-defense.

"Experienced federal prosecutors will determine whether the evidence reveals a prosecutable violation of any of the limited federal criminal civil rights statutes within our jurisdiction, and whether federal prosecution is appropriate," the statement said.