The Ohio man accused of slamming into demonstrators as they protested a white supremacist rally last year in Charlottesville, Virginia, has been charged with federal hate crimes, Justice Department officials announced Wednesday.

James Alex Fields Jr., 21, is accused of slamming a car into protesters on Aug. 12, 2017, at the “Unite the Right” rally in Charlottesville, killing 32-year-old Heather Heyer and injuring several others.

A federal grand jury in Virginia on Wednesday indicted Fields on 30 hate crime-related charges in connection to the car attack. U.S. Attorney General Jeff Sessions said in a statement that the indictment “should send a clear message to every would-be criminal in America that we aggressively prosecute violent crimes of hate that threaten the core principles of our nation.”

Fields is accused of driving his car into a crowd gathered in protest of the “Unite the Right” rally, a demonstration organized by white supremacists to oppose the removal of a Confederate memorial from the Charlottesville’s Emancipation Park.

Heather Heyer's Parents At Memorial Service

In an indictment, authorities said Fields watched the crowd from his idling vehicle before slowly reversing to the top of a nearby hill and then rapidly accelerating. Authorities said he ran through a stop sign and across a raised pedestrian mall, directly into the crowd.

“Fields’s vehicle stopped only when it struck another vehicle near the intersection,” Justice Department officials said Wednesday in a news release. “He then rapidly reversed his vehicle and fled the scene.”

The attack came after the rally had descended into chaos — with violent brawling between attendees and counterdemonstrators — and authorities had forced the crowd to disband. Fields had been photographed hours beforehand with a shield bearing the emblem of Vanguard America, one of the hate groups that took part, although the group denied any association with him. Fields was described by his former high school teacher as a Nazi sympathizer.

Fields already faces state charges including first-degree murder. He has been in custody since the rally.

The Associated Press contributed to this report.