4 'white supremacists' charged with attacking counterprotesters in Charlottesville

Four men who authorities said were pictured violently hitting counterprotesters at the 2017 Unite the Right rally in Charlottesville are now facing federal charges.

Government investigators used Facebook and social media posts to connect four California men with a "militant white-supremacist organization" and place them at the Charlottesville rally using social media posts and bank records, according to a federal arrest affidavit.

Beyond that, authorities said they were able to identify the men in footage from the Aug. 12, 2017, rally, picturing them attacking other attendees.

The men - Benjamin Drake Daley, Michael Paul Miselis, Thomas Walter Gillen, Cole Evan White - were charged under the riot act. The charge is not related to the death of Heather Heyer, who was killed during the rally.

The charging document released by U.S. Attorney for the Western District of Virginia Thomas T. Cullen Tuesday alleges that the men violated the riot act in either inciting a riot, traveling to participate in a riot, committing any act of violence during a riot, or aiding or abetting any person in inciting or participating in a riot.

Cullen said today that "the riots act was a more appropriate charge" than charging them under a hate crimes statute, since that would require ascribing the motivations of the individuals actions, though he did say it would be possible for additional charges to be added.

Officials were "more comfortable that the riot act was a better fit," Cullen said.

The charging document details the steps taken by officials to determine that the four men were "at least four members and associates of the 'Rise Above Movement,' (RAM) a militant white-supremacist organization based in Southern California."

From there, investigators say they were able to place the men on the ground in Charlottesville on Aug. 11, the night of the torch-lit rally on the grounds of the University of Virginia, and in greater Charlottesville on Aug. 12, the day of the formal Unite the Right rally.

In one Facebook post, Daley allegedly chastised "another prominent white supremacists for releasing a chemical spray" because, he wrote, "We had them[m] completely surrounded. I hit like 5 people," according to the charging documents.

These men assaulted an African American man, two females, and a minister at the "Unite the Right" rally, Cullen said. They have participated in "acts of violence and brutality" at other rallies across California, according to Cullen.

If convicted, each defendant faces up to 10 years in prison, Cullen said. Their attorneys could not be reached for comment.

"These guys came to Charlottesville to commit violent acts and it wasn’t the first time they’ve done it," Cullen said.

All four men are currently in custody in California.

ABC News' Amanda Maile contributed to this report.