OAKLAND (CBS SF) — The man accused of killing a federal officer in Oakland during George Floyd protests in May on Thursday entered a not guilty plea.

32-year-old Steven Carrillo appeared in a video conference Thursday morning with a defense attorney assigned to him.

READ MORE: Home Alone: Helping Pandemic Pets Cope When Their Owners Return To Work

Oakland Federal Building Shooting:

Carrillo is a former leader of a U.S. Air Force anti-terror squadron.

READ MORE: Neighbors Creating Holiday Magic On Candy Cane Lane In Pleasanton Since 1953

He and a second suspect are accused of killing federal security officer Dave Patrick Underwood and wounding a second officer in front of the Oakland federal building during the late May protest.

A federal grand jury indicted Carrillo for murder and attempted murder in the Oakland slaying Monday.

Carrillo faces separate charges in an ambush in Santa Cruz that killed a sheriff’s sergeant last month.

MORE NEWS: As Oakland Lawmakers Prepare To Vote To Increase Police Staffing New Report Questions Need

Authorities said Carrillo specifically targeted law enforcement. His next hearing is August 6th.