A U.S. firearms group has raised more than $12,000 on behalf of George Zimmerman to buy more guns or a security system for protection.

According to Zimmerman's attorney and his brother, he is concerned about his safety and has been receiving death threats since he was acquitted in the fatal shooting of unarmed black teenager Trayvon Martin on July 13, 2013. The 29-year-old former neighborhood watch volunteer claims that he shot Martin in self-defense after he stalked and confronted the teen, who was walking home from a convenience store.

On Tuesday, the Buckeye Firearms Foundation, an Ohio-based gun advocacy group, cut Zimmerman a check for $12,150.37 to purchase more guns, reports Think Progress.

According to the Buckeye Firearms Foundation, Zimmerman's gun rights are being violated by the U.S. Department of Justice which has taken all the evidence from the trial, including the gun that killed Martin, as part of a civil rights investigation, reports USA Today.

The foundation's donation for Zimmerman is meant to be spent on guns, ammunition, protective gear or a security system, said Ken Hanson, the group's legal chairman.

"The Department of Justice refused to return him his gun, and he's in need of protection," Hanson said. "The money is intended to be used for anything he needs to defend himself or his family. He has complete discretion on how to use the money."

However, the money could be used to pay for Zimmerman's defense costs and fees.

Zimmerman's spokesman, Shawn Vincent, said that although Zimmerman has been offered free guns, he has not accepted such donations.