In a startling precursor to what could be the most explosive testimony in Donald J. Trump’s criminal trial, the judge on Friday told prosecutors that he was personally asking that a key witness halt his statements about the former president.
The witness, Michael D. Cohen, was a personal lawyer for Mr. Trump, who in 2016 paid $130,000 in hush money to a porn star to silence her account of extramarital sex with him. Mr. Cohen is expected to begin testifying next week, and has been outspoken in his taunting of Mr. Trump, including by posting a TikTok video in which he wore a shirt with a picture of the former president behind bars.
On Friday, moments after prosecutors acknowledged that they have little control over their star witness, the judge, Juan M. Merchan, asked them to tell Mr. Cohen to refrain from making any more statements about the case.
And he made it clear that was from the highest authority in the court: him.
“That comes from the bench,” Justice Merchan said.
The judge’s admonition injected a sense of anticipation into an otherwise placid proceeding, perhaps the first routine day in a most unroutine trial. Prosecutors from the Manhattan district attorney’s office steadily tightened their focus on the central accusations against Mr. Trump ahead of what they said could be their final week of witness testimony.
They prepared for Mr. Cohen’s arrival by calling so-called custodial witnesses, who stitched together testimony with documents, phone logs, and text and email messages — much of it relevant to Mr. Cohen. Such witnesses are used to authenticate documents and events, points of fact that prosecutors and defense lawyers have not otherwise previously agreed on.
Between the riveting testimony of the porn star, Stormy Daniels, and Mr. Cohen’s looming appearance, Friday’s session was a moment of calm in the eye of the storm that is the first criminal trial of an American president.
Mr. Trump is charged with 34 felonies, accused of orchestrating the falsification of documents — 11 invoices, 11 checks and 12 ledger entries — that were used to reimburse Mr. Cohen. Mr. Trump has pleaded not guilty and has denied having had sex with Ms. Daniels.
Friday’s most substantive witness was Madeleine Westerhout, a former executive assistant during Mr. Trump’s presidency who had direct insight into how documents flowed in and out of the Oval Office.
Ms. Westerhout testified that Mr. Trump would sign checks sent from his family business, the Trump Organization, often stapled to the related invoices. She said she saw him sign them at the Resolute Desk and sometimes, in Sharpie.
She also testified that she had helped schedule a February 2017 meeting between Mr. Cohen and Mr. Trump in the White House. There, Mr. Cohen is expected to testify, he and Mr. Trump discussed reimbursement for the $130,000 payment to Ms. Daniels.
During cross-examination on Thursday, Susan Necheles, a defense lawyer, elicited warm testimony from Ms. Westerhout, who said that Mr. Trump had been “a really good boss” who cared for his wife and family.
Those statements bolstered a key component of the defense’s case. Mr. Trump’s lawyers have argued that he was motivated to pay Ms. Daniels not to win the election, as prosecutors have said, but rather “to protect his family, his reputation and his brand” from “salacious allegations.”
But Ms. Westerhout missed a chance to further that case Friday. Ms. Necheles asked the former executive assistant about Mr. Trump’s reaction in 2018 after Ms. Daniels’s story became public.
While Ms. Westerhout acknowledged that “the whole situation was very unpleasant,” she said that her former boss had not brought up his family.
Shortly before Ms. Westerhout took the stand, the jury got a chance to assess Ms. Daniels’s story for themselves.
Beginning on Tuesday, Ms. Daniels was on the stand for more than seven hours. She described, in often graphic detail, her account of a liaison with Mr. Trump in a Lake Tahoe, Nev., hotel suite in 2006. Though not directly related to the charges, the encounter — a brief and fraught experience, as recounted by Ms. Daniels — was the impetus for the hush-money payment made by Mr. Cohen, and for the case itself.
Mr. Cohen was once one of Mr. Trump’s closest confidants and most loyal enforcers. But he has since become a bitter enemy, openly mocking the former president and his legal travails.
Mr. Trump has returned fire, calling Mr. Cohen a liar and reposting similar attacks by allies. It was those broadsides, in part, that prompted Justice Merchan to prohibit Mr. Trump from attacking witnesses and jurors, among others. The judge has since found the former president to have violated that order 10 times, and fined him $10,000. On Tuesday, Justice Merchan threatened Mr. Trump with jail if the violations continue.
Mr. Cohen, a felon who pleaded guilty to a raft of federal crimes in 2018, some of which he said were executed at Mr. Trump’s direction, is an imperfect witness. He has already been introduced to the jury by others who spoke of him from the stand, often in unflattering terms. The jury has heard his voice — in secretly recorded conversations, with Mr. Trump and others — and seen a photo of him beaming in the White House. But Monday, he is expected to appear in person.
On Friday, jurors got a taste of Mr. Trump’s disdain when prosecutors displayed Twitter posts disparaging Mr. Cohen, including one in August 2018, a day after Mr. Cohen’s plea deal was announced.
“If anyone is looking for a good lawyer, I would strongly suggest that you don’t retain the services of Michael Cohen!” the former president wrote.
A prosecution paralegal, Georgia Longstreet, doubled as a witness, guiding the courtroom through texts between Dylan Howard, the onetime editor of The National Enquirer, and Gina Rodriguez, Ms. Daniels’s manager in 2016. The messages showed a negotiation that led to a deal brokered by representatives of The National Enquirer but executed by Mr. Cohen.
Prosecutors have argued that the supermarket tabloid entered a conspiracy with Mr. Trump and Mr. Cohen to unlawfully influence the 2016 presidential election.
Mr. Trump has characterized the case as a political persecution, brought by the Manhattan district attorney, Alvin L. Bragg, a Democrat. During the former president’s four weeks inside Justice Merchan’s courtroom, he has been a glum and glowering figure, staring straight ahead or occasionally at a collection of positive press notices, printed for him daily by an aide.
Many other times, however, Mr. Trump has shut out the testimony around him, closing his eyes for long stretches.
That habit was particularly pronounced during Ms. Daniels’s testimony, which his defense team furiously tried to discredit, suggesting that she was a liar and fabulist, intent on peddling a false story of an affair for personal gain. They called twice for a mistrial, arguing that her testimony had poisoned the jury. The judge rejected both attempts.
For her part, Ms. Daniels was initially uneven — speeding through testimony and earning rebukes from the judge for straying off topic — before finding her footing in cross-examination. She batted back questions and insinuations from Ms. Necheles, the defense lawyer.
Mr. Trump’s lawyers are expected to be equally aggressive with Mr. Cohen, who will likely bring a glare of attention to the courtroom. And while the pressure will be on the witness, the moment is likely to also be intense for Mr. Trump, who once predicted that Mr. Cohen would never turn against him.
“Sorry I don’t see Michael doing that,” Mr. Trump wrote on Twitter in April 2018. “Despite the horrible Witch Hunt and the dishonest media!”
