A member of a white supremacist group pleaded guilty Monday to conspiring to riot at a white nationalist rally in Virginia and at other demonstrations in California.

Thomas Walter Gillen, 25, of Redondo Beach, California, became the second member of the Rise Above Movement to plead guilty after four members of the group were indicted in Virginia last year. Members of the militant white supremacist group are known for meeting regularly to train in mixed martial arts street-fighting techniques.

Cole Evan White, of Clayton, California, pleaded guilty to the same charge in November.

All four men were accused of committing violent acts during a torch-lit march at the University of Virginia and the “Unite the Right” rally in Charlottesville in August 2017.

Defense lawyers for two of the men had argued that their actions were protected by the constitutional right to free speech and assembly.

U.S. Attorney Thomas Cullen said in a statement Monday that the First Amendment “does not license insensate acts of violence committed under the guise of First Amendment expression.”

As part of Gillen’s guilty plea, he admitted that he and other members of RAM attended the Unite the Right rally and other demonstrations in California “to incite and commit acts of violence, not to exercise their rights to free speech.”

Gillen’s lawyer did not return a call seeking comment Monday.

Prosecutors said Gillen and other RAM members joined hundreds of people at the march on the grounds of the University of Virginia on Aug. 11, 2017. The march ended near a statue of Thomas Jefferson, where a group of students had gathered to protest white supremacy. Violence erupted, with some people kicking, punching, spraying chemical irritants and swinging torches. Prosecutors said that during this riot, RAM members, including Gillen, struck multiple people with a torch.

The next day, Gillen and other members of RAM were part of a group that clashed with people who had come to the Unite the Right rally to protest against discrimination. Prosecutors said the RAM members “collectively pushed, punched, kicked … head-butted, and otherwise assaulted several people, resulting in a riot.”

Later that day, anti-racism protester Heather Heyer was killed when a self-avowed white supremacist drove his car into a crowd of counterprotesters. James Alex Fields Jr. was convicted of murder and other crimes in state court. Last month, Fields pleaded guilty to federal hate crime charges.

Prosecutors said Gillen and other RAM members also committed violent acts at other 2017 demonstrations and rallies in Huntington Beach and Berkley, California.

A third defendant, Michael Paul Miselis, has a change-of-plea hearing scheduled Friday in U.S. District Court in Charlottesville.