A federal jury on Tuesday convicted the first defendant to face trial for participating in the Jan. 6 attack on the U.S. Capitol, finding a Texas man with ties to an anti-government militia guilty of all five charges he faced.

The verdict is a significant milestone in the U.S. Justice Department’s investigation of the Capitol riot, an assault by supporters of former President Donald Trump on the seat of American democracy that forced lawmakers to flee in fear of their lives and delayed and threatened to upend the peaceful transfer of power.