Judge Merchan has begun hearing arguments about the admissibility of some defense exhibits, including an email communication between Michael Cohen and his one-time attorney Bob Costello's law partner Jeffrey Citron.

Defense attorney Todd Blanche argued that the exhibit could be used to impeach Cohen's testimony.

Judge Merchan said he will not allow the email into evidence. Prosecutors argued that the email was hearsay and cannot fairly offer a window into Cohen's state of mind.

"There is another layer there of hearsay," Merchan said about the email. "I don't see any probative value for impeachment purposes here at all."

"Good morning Mr. Trump," Judge Juan Merchan said as he gaveled in the proceedings.

"It's become apparent that we are not going to be able to sum up tomorrow," the judge said after taking the bench.

Merchan said it's more likely summations will take place next Tuesday, after procedural matters and the Memorial Day break.

"Either have a long break now or a long break then, and unfortunately the calendar is what it is," the judge said.

Prosecutors have entered the courtroom for Day 19 of the trial.

Trump has arrived with his entourage.

Before entering, the former president addressed reporters but ignored their questions about whether he'll testify in the trial.

Donald Trump's former attorney Michael Cohen returns to the witness stand this morning for the final time before prosecutors rest their case against the former president in his criminal hush money trial.

Prosecutors could rest their case later this morning.

Defense attorneys have not yet declared who they plan to call to testify -- including whether Trump will testify in his own defense.

Cohen, the prosecution's last major witness, is expected to complete his cross-examination by Trump's defense team before lunch.

Proceedings are scheduled to get underway at 8:45 a.m. ET with arguments over the admission of additional exhibits, after which the jury is expected back in court at 9:30 a.m.

Under cross-examination from prosecutor Susan Hoffinger, Michael Cohen's former attorney Robert Costello testified that he first met with Cohen at the urging of Jeffrey Citron, who scheduled the April 2018 meeting at the Regency Hotel.

Costello -- who has represented Leona Helmsley and George Steinbrenner in the past -- acknowledged that representing Cohen would have generated positive publicity for his law firm. But Costello said he did not have positive feelings about landing Cohen as a client.

"I didn't want him as a client with the firm," Costello said, pushing back on prosecutors' assertions that landing Cohen would have been a big win.

Jurors briefly saw an email where Costello's son congratulated him for landing Cohen as a client.

"Wow. That's big news. Congrats Dad. I hope this leads to a lot of good things coming your way," Costello's son wrote.

Asked about the FBI's raid on Cohen's office and hotel room, Costello said, "I wouldn't use the term raid -- they executed a search warrant."

"He was suicidal that day and acting very manic," Costello said about Cohen's behavior after the FBI searched on his hotel and office.

""You thought he was being a drama queen, didn't you?" Hoffinger asked.

"He was putting on quite a show and he explained to us that two nights before he was on the roof of the Regency Hotel and he was going to jump off and kill himself because he couldn't handle the pressure," Costello said.

Testimony subsequently concluded for the day, with Costello scheduled to return to the stand tomorrow.