Judge quits courtroom after cross-examination of Trump witness Costello.

 Judge Juan Merchan barred jurors, onlookers, and members of the press from the courtroom Monday afternoon as he berated a key Donald Trump defense witness for making an ill-tempered remark about the judge’s decisions.

Just after the prosecution wrapped up its case in President Donald Trump’s long-running hush money trial, defense attorney Robert Costello mouthed after Merchan objected to several parts of Costello’s testimony. When Costello was confronted by Merchan about breaking courtroom protocol, Costello asked the judge to strike it off the record, which only the judge can do.

Merchan then excused the jury and began berating Costello, an ex-federal prosecutor and seasoned defense lawyer, asking, “Are you looking at me right now?” The judge then briefly adjourned the courtroom.

Costello is a crucial defense witness. Michael Cohen, President Donald Trump’s former attorney, has said that Costello tried to act as a middleman between him and the President after the FBI executed a search warrant at Cohen’s office in January 2018.

Costello will take the stand again on Tuesday, though it is unclear whether Mr. Trump will testify.

Mr. Trump, the first former president to be charged with a criminal offense, is accused of falsifying business documents to conceal payments made to porn actress Stormy Daniels on behalf of Mr. Trump before the 2016 election.