The federal charges against Dylann Roof are expected to be made public later on Wednesday, according to National Public Radio. The New York Times also reported the pending federal charges.
US Attorney General Loretta Lynch is scheduled to hold a press briefing at 3 p.m., but the Justice Department did not say what she would address.
Representatives for the department could not be reached to immediately confirm the reported hate crime charges.
Roof, 21, has already been charged with nine counts of murder in South Carolina in the June 17 shooting. If found guilty, he could face the death penalty. He also faces three counts of attempted murder.
Authorities have been investigating the shooting as a possible hate crime, examining a racist manifesto that appeared online and seemed to be authored by Roof, who is white.
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