Journalists and spectators were cleared from the chamber during extensive closed-door sessions at President Bill Clinton’s impeachment trial in 1999. Our chief Washington correspondent explains the rules.

Art Lien, a courtroom sketch artist who normally covers the Supreme Court, will be capturing the scene in the Senate, where no photographs are allowed.

Yesterday: With the formal opening of the trial, senators swore to deliver “impartial justice” and installed Chief Justice John Roberts to preside. Here’s a step-by-step guide to the process.

Related: The nonpartisan Government Accountability Office said the Trump administration violated the law when it withheld nearly $400 million in congressionally approved aid to Ukraine last summer, a decision at the heart of the impeachment case.

News analysis: The trial starts as more details emerge about the effort to pressure Ukraine to pursue Mr. Trump’s political rivals, and “the missing information, like almost everything else in Washington these days, is seen through drastically different lenses,” our chief White House correspondent writes.