A U.S. Air Force sergeant with ties to an anti-government extremist group has been charged in the shooting death of a federal courthouse security officer in Oakland, California.   Staff Sergeant Steven Carillo is accused of killing David Patrick Underwood and wounding his partner in a drive-by shooting on May 29 during a violent protest over the death of George Floyd, a black man who died as he was being arrested by police in Minneapolis earlier that month.   Robert Alvin Justus, the man prosecutors say drove Carillo’s vehicle, has been charged with aiding and abetting the Oakland attack. Carillo has been in state custody since June 6 on charges of killing an officer with the Santa Cruz County sheriff’s department and the wounding of four other officers outside of San Francisco.  The sheriff’s department says the officers were investigating a tip that the vehicle used in the Oakland shooting had been located when they were ambushed by Carillo.  Carillo engaged in a gun battle with the officers, then stole a car in an attempt to escape before he was eventually arrested.  Authorities say Carillo is a follower of the so-called “boogaloo” movement, prominent on social media, which calls on its followers to prepare for a violent uprising against the U.S. government. Carillo and Justus allegedly planned the Oakland attack during an online chat with a third person the day before.  A search of his van turned up a bullet-proof vest with a boogaloo insignia patch sewn on it.   Three other men associated with the boogaloo movement were arrested by the FBI earlier this month in Las Vegas and charged with planning to incite violence and cause destruction during a Black Lives Matter protest.