The Justice Department is telling Sanford, Florida, police: Don't give George Zimmerman his gun back.
The Feds have placed a hold on all evidence from his trial.
They're looking at whether he should face civil rights charges in the shooting death of 17-year-old Trayvon Martin last year.
Last weekend, an all female jury found Zimmerman not guilty of any criminal charges.
That verdict has led Reverend Al Sharpton to organize what he's calling "Justice for Trayvon" day tomorrow.
Rallies are planned for at least 100 cities Saturday, July 20, including L.A., New York, and Miami.