The ex-president is accused of felony charges related to the falsification of business records aimed at concealing a sexual scandal with a pornographic actress.

The criminal trial of Donald J. Trump, the 45th president of the United States and the presumptive nominee of the Republican Party, commenced on Monday as potential jurors gathered in a nondescript courtroom in New York City, with Trump in attendance.

Trump faces charges in Manhattan, a strongly Democratic area and his former residence, alleging the falsification of nearly thirty business records to conceal a payment made to Stormy Daniels, a pornographic actress who claims to have had a brief encounter with him in 2006.

Trump denies the encounter and asserts his innocence, alleging that the charges are politically motivated. He has criticized both the judge, Juan M. Merchan, and the Manhattan district attorney, Alvin L. Bragg, a Democrat, who were present on the first day of the trial.

Facing 34 felony counts, Trump could potentially receive probation or up to four years of imprisonment.

The trial, expected to span several weeks, features a notable roster of potential witnesses including Michael Cohen, Trump’s former lawyer who facilitated the payment; Karen McDougal, a Playboy model who alleges an affair with Trump; and Hope Hicks, a former aide to Trump. Stormy Daniels herself may also testify.

Before proceeding with the trial, the process of selecting a jury must be completed, which commenced on Monday.

Here are five key observations from Mr. Trump’s initial day in court:

1. Justice Merchan maintains a stern demeanor, which hasn’t worked in favor of the defense. Justice Merchan, an experienced New York judge, has consistently rejected defense motions, including those related to the belated disclosure of documents by prosecutors and attempts to postpone or dismiss the case. On Monday, Justice Merchan continued his pattern of rejecting defense motions, including one attempting to compel his recusal. The defense had raised concerns, such as the fact that his daughter is a Democratic political consultant. Furthermore, Justice Merchan ruled in favor of prosecutors being allowed to present evidence regarding Trump’s collaboration with The National Enquirer to bolster his 2016 presidential campaign through publicity efforts. Despite Trump’s legal team characterizing this evidence as a distraction, they were unsuccessful in their argument. However, Trump’s lawyers did manage to persuade Justice Merchan that introducing sexual assault allegations against Trump following the release of the Access Hollywood tape, in which Trump boasted about inappropriate behavior towards women, would unfairly prejudice the former president. Consequently, Justice Merchan deemed these allegations inadmissible during the trial, dismissing them as unfounded rumors and hearsay.
2. 
   The trial encompasses more than just business records.
3. Justice Merchan’s rulings on Monday emphasized that the proceedings will delve into uncomfortable aspects of the former president’s life, including the Access Hollywood tape and other events that Trump attempted to suppress, such as an alleged affair with Ms. McDougal. Justice Merchan stated that both topics could be addressed during the trial. In a minor victory for the defense, the judge maintained that the actual Access Hollywood tape would not be played, but Trump’s exact words could be recounted in the court record. Nevertheless, the majority of Justice Merchan’s decisions suggested that the trial will feature revealing details from Trump’s personal history.
4. Despite Trump’s claims of contentment, his demeanor indicates otherwise.
5. Upon entering the courtroom, Mr. Trump expressed being “very proud to be here.”
6. However, when facing Mr. Merchan, Mr. Trump appeared noticeably less enthusiastic. He displayed signs of disinterest, such as slouching, scowling, and scoffing. Moreover, he maintained an unusual silence, which contrasts with his usual demeanor characterized by sharp attacks and aggressive remarks that defined his political career.
7. During the court session, the former president spoke only briefly, answering a few questions from Justice Merchan regarding procedural matters and acknowledging the consequences of disrupting the proceedings—possible removal from the courtroom or imprisonment. He did engage in whispered conversations with his lawyers. When the prosecution played a recording of him expressing respect for women, he silently affirmed the statement by mouthing the word “true.”
8. However, overall, the experience seemed taxing for Mr. Trump; at one instance before lunch, he seemed to doze off.
9. This trial may take a while.
10. It’s easy to underestimate the time required for even small tasks in legal proceedings. On Monday, the morning session primarily consisted of strategic moves by both prosecutors and the defense, while prospective jurors remained on standby. By lunchtime, they were still awaiting further proceedings.
11. The process of jury selection could extend over several days or even weeks, with the trial itself potentially lasting for two months. Justice Merchan noted that delays might occur due to the Passover holiday, although he suggested the possibility of compensating for lost time by scheduling court hearings on Wednesdays, which had initially been designated as a non-working day.
12. We are on our way to picking a jury. Slowly.
13. In the afternoon, prospective jurors eventually entered Justice Merchan’s courtroom. He greeted them warmly, introduced the lawyers and Mr. Trump, and provided them with an overview of the case.
14. Justice Merchan inquired whether any prospective jurors believed they couldn’t impartially judge the former president. Out of the 96 individuals present, over 50 raised their hands and were promptly dismissed.
15. The remaining jurors were subjected to a series of 42 questions each. By the conclusion of Monday, 11 jurors had been interrogated, and two more were excused: one woman who admitted bias and another man who cited a potential scheduling conflict with his child’s wedding.