Enrique Tarrio, the former chairman of the Proud Boys, and four other members of the far-right group were indicted on Monday for seditious conspiracy in connection with the storming of the Capitol last January, the most serious crime to be charged in the Justice Department’s sprawling investigation of the assault. The sedition charges against Mr. Tarrio and his co-defendants — Joseph Biggs, Ethan Nordean, Zachary Rehl and Dominic Pezzola — came in an amended indictment that was unsealed in Federal District Court in Washington. The men had already been charged in an earlier indictment filed in March with conspiring to...