SAN FRANCISCO (AP) — A former U.S. Air Force sergeant with alleged ties to the “boogaloo” movement has pled guilty to the 2020 fatal shooting of a federal security officer in the San Francisco Bay Area.

Steven Carrillo pled guilty Friday to a federal murder charge in the killing of David Patrick Underwood, a federal security guard. Underwood was shot May 29, 2020, while standing outside an Oakland federal building amid large protests against police brutality following the killing of George Floyd in Minneapolis.

Prosecutors say Carrillo had ties to the “boogaloo” movement. It’s a concept embraced by a loose network of gun enthusiasts and militia-style extremists.