Eleven people including Stewart Rhodes, the leader and founder of the right-wing militia group the Oath Keepers, have been indicted on charges of seditious conspiracy, marking an escalation of the Justice Department’s investigation into the attack on the U.S. Capitol on Jan. 6 last year. An indictment unsealed Thursday accused Mr. Rhodes, 56 years old, of organizing an armed plot to storm the Capitol and stop the certification of President Biden’s election victory. The case marks the first time the Justice Department has filed charges of sedition in connection with the attack and comes days after Attorney General Merrick Garland...