NEW YORK — Jury deliberations began Wednesday in Donald Trump’s hush money trial, placing the outcome of the history-making case in the hands of a dozen New Yorkers who have vowed to be fair and impartial in the face of their unprecedented task.

The jury of seven men and five women was sent to a private room just before 11:30 a.m. to begin weighing a verdict in the first criminal trial of a former U.S. president. The jurors’ discussions will be secret, though they can send notes to the judge asking to rehear testimony or see evidence. That’s also how they will notify the court of a verdict, or if they are unable to reach one.

“It is not my responsibility to judge the evidence here. It is yours,” Judge Juan M. Merchan told jurors.

Trump struck a pessimistic tone after leaving the courtroom following an hourlong reading of jury instructions, repeating his assertions of a “very unfair trial” and saying: “Mother Teresa could not beat these charges. These charges are rigged.”

Trump and his lawyers, along with prosecutors, were instructed to remain inside the courthouse during deliberations. He learned back in his chair and closed his eyes as Merchan told jurors at the outset of the day that he would take about an hour to read the instructions. As the instructions continued, he wrote notes that he showed to one of his lawyers.

Trump is charged with 34 counts of falsifying business records at his company in connection with an alleged scheme to hide potentially embarrassing stories about him during his 2016 Republican presidential election campaign.

The charge, a felony, arises from reimbursements paid to then-Trump lawyer Michael Cohen after he made a $130,000 hush money payment to porn actor Stormy Daniels to silence her claims of that the two had sex in 2006. Trump is accused of misrepresenting Cohen’s reimbursements as legal expenses to hide that they were tied to a hush money payment.

Trump has pleaded not guilty and contends the Cohen payments were for legitimate legal services. He has also denied the alleged extramarital sexual encounter with Daniels.

To convict Trump, the jury will have to find unanimously that he created a fraudulent entry in his company’s records, or caused someone else to do so, and that he did so with the intent of committing or concealing another crime.

The crime prosecutors say Trump committed or hid is a violation of a New York election law making it illegal for two or more conspirators “to promote or prevent the election of any person to a public office by unlawful means.”

While the jury must unanimously agree that something unlawful was done to promote Trump’s election campaign, they don’t have to be unanimous on what that unlawful thing was.

The jurors — a diverse cross-section of Manhattan residents and professional backgrounds — often appeared riveted by testimony in the trial, including from Cohen and Daniels. Many took notes and watched intently as witnesses answered questions from Manhattan prosecutors and Trump’s lawyers.

Jurors started deliberating after a marathon day of closing arguments in which a prosecutor spoke for more than five hours, underscoring the burden the district attorney’s office faces in needing to establish Trump’s guilt beyond a reasonable doubt.

A defense lawyer spoke for about half that time; the Trump team need not establish his innocence to avoid a conviction but must instead bank on at least one juror finding that prosecutors have not sufficiently proved their case.

Earlier Wednesday, the jury received instructions in the law from Merchan, who offered some guidance on factors the panel can use to assess witness testimony, including its plausibility, its consistency with other testimony, the witness’ manner on the stand and whether the person has a motive to lie.

But, the judge said, “there is no particular formula for evaluating the truthfulness and accuracy of another person’s statement.”

The principles he outlined are standard but perhaps all the more relevant after Trump’s defense leaned heavily on questioning the credibility of key prosecution witnesses, including Cohen.

Merchan also instructed jurors on the concept of accessorial liability, under which a defendant can be held criminally responsible for someone else’s actions.

That’s a key component of the prosecution’s theory of the case because, while Trump signed some of the checks at issue, people working for his company processed Cohen’s invoices and entered the transactions into its accounting system.

In order to hold Trump liable for those actions, Merchan said jurors must find beyond a reasonable doubt that he solicited, requested or commanded those people to engage in that conduct and that he acted intentionally.

Prosecutor Joshua Steinglass touched on accessorial liability in his closing argument Tuesday, telling jurors: “No one is saying the defendant actually got behind a computer and typed in the false vouchers or stamped the false invoices or printed the false checks.”

“But he set in motion a chain of events that led to the creation of the false business records,” Steinglass said.

Any verdict must be unanimous. During deliberations, six alternate jurors who also sat through every minute of the trial will be kept at the courthouse in a separate room in case they are needed to replace a juror who falls ill or is otherwise unavailable. If that happens, deliberations will start anew once the replacement juror is in place.