(CNN) -- Florida authorities have delivered all evidence related to the George Zimmerman investigation to federal officials, who are weighing whether to pursue a civil rights case.

The Sanford Police Department said it turned over all evidence, including a gun, to the Department of Justice on Monday.

Justice officials are investigating whether Zimmerman violated Trayvon Martin's civil rights when he shot the African-American teenager.

Zimmerman, a former neighborhood watch volunteer, was acquitted of second-degree murder and manslaughter charges on July 13 after claiming he fired in self-defense. The shooting occurred in February last year.

Attorney General Eric Holder has said the Justice Department will "act in a manner that is consistent with the facts and the law." Holder described Martin's shooting as " tragic, unnecessary," and said a thorough investigation will be conducted.

"Independent of the legal determination that will be made, I believe that this tragedy provides yet another opportunity for our nation to speak honestly about the complicated and emotionally charged issues that this case has raised," Holder said last week. "We must not -- as we have too often in the past -- let this opportunity pass."

Justice officials opened an investigation into the Zimmerman case last year, and will include testimony from the Florida trial.

Various civil rights groups have protested nationwide to demand the Justice Department bring federal charges against Zimmerman.

A petition by the NAACP has reached 1.5 million signatures, the civil rights organization said on its website.