Chief Justice John G. Roberts Jr. officially began the third presidential impeachment trial in U.S. history Thursday. Shortly after arriving at the Capitol, Senate President Pro Tempore Charles E. Grassley swore in the justice on the Senate rostrum.

Roberts then administered the oath to lawmakers. Alphabetically and in groups of four, the senators’ names were read by the clerk and the senators approached the Republican desk — normally used by Republican floor staff — to sign the impeachment oath book.

Julie E. Adams, secretary of the Senate, closed the book at 2:30 p.m. Shortly after, Senate Majority Leader Mitch McConnell read through some procedural language and adjourned the court of impeachment until Tuesday, Jan. 21 at 1 p.m.