Jurors will deliberate until 4:30 p.m. ET today if they don't reach a verdict sooner, Judge Merchan said.

"You cannot leave the building and you need to be able to get here quickly" when a verdict is reached, the judge told the parties after the jury had left the courtroom.

Former President Trump got up from the defense table and spoke with several associates, then exited the courtroom with his entourage.

The staff and lawyers from the Manhattan district attorney's office also left the courtroom.

As the 12 main jurors left the courtroom, most appeared to look away from Trump as they passed his counsel table.

The six alternate jurors remained in the courtroom after the 12 main jurors left to begin deliberations.

"We are not going to excuse you just yet," Judge Merchan told the alternates,

He asked them to stick around through the deliberations. though they won't participate in the deliberations themselves.

"That concludes my instructions on the law. Counsel please approach," Judge Merchan said when he was done instructing the jury.

He held a sidebar with the attorneys, after which the jurors filed out of the courtroom to begin deliberations.

Judge Merchan emphasized that jurors each need to come to an individual decision about the verdict after hearing and understanding the view of the other jurors.

"Each of you must decide the case for yourself, but only after a fair and impartial consideration of the evidence with the other jurors," Merchan said.

"You should discuss the evidence and consult with each other, listen to each other, give the others' views careful consideration," he said. "You should not surrender an honest view of the evidence simply because you want the trial to end, or because you're outvoted."

"Your verdict on each count you consider must ... be unanimous -- that is, each and every juror must agree to it," Merchan said.

Merchan said that the jury foreperson will read the verdict for each of the charged counts. Merchan will then poll the entire jury to confirm their verdict.

As ABC News reported previously, the U.S. Secret Service spent considerable time working with New York City court and jail officials to determine what would happen if the judge, as threatened during trial, ordered former President Trump to be incarcerated for contempt -- a situation that did not come to pass.

According to an official briefed on the matter, U.S. Secret Service planners have not started the process of determining arrangements for Trump to be imprisoned at a New York state penitentiary in the event he is convicted. Because Trump is charged with nonviolent crimes, has no criminal record, and was allowed to remain free before trial, it is believed that there is no way that a conviction would lead to immediate incarceration.

If Trump is convicted, the Secret Service will spend the time prior to sentencing -- which could be months -- working with New York state prison officials to determine how imprisonment would work. An official told ABC News that potential questions could include, would USSS agents be armed inside prisons where firearms are prohibited? What prison would Trump be assigned to? Where would protection agents be stationed in relation to Trump? Those details, among many others, would have to be hammered out, the official said.

The Secret Service specifically avoided planning on a possible prison sentence during the trial so Trump and his loyalists could not accuse them of taking sides against the former president, the official said.

-Josh Margolin