Donald Trump faced forward and did not appear to make eye contact with any jurors as they entered the courtroom and took their seats in the jury box.

Before any of the lawyers in the case could speak a word, Judge Merchan launched into a lengthy speech outlining how the trial will work.

"We are about to begin the trial of People of the State of New York v. Donald Trump," Merchan told the 12 jurors and six alternates.

Merchan emphasized that the burden of proof rests on the prosecutors and that jurors should presume that Trump is innocent. A guilty verdict requires that each juror determines that the state proved their case beyond a reasonable doubt, Merchan said.

"The defendant is presumed to be innocent," Merchan said. "It is not sufficient to prove that the defendant is probably guilty."

Merchan attempted to set expectations for the jurors, only two of which have ever served on a jury before. For example, Merchan told the jurors not to expect the lawyers to launch into lengthy speeches outside of the opening and closing statements.

"That happens in TV and in movies, but it doesn't happen in real trials," Merchan said.

Judge Juan Merchan ruled that if Trump takes the stand, prosecutors can question him about a number of previous legal issues -- but the judge limited the scope of the cases and the extent to which prosecutors can question him about the facts of those cases.

The ruling is a mixed bag for Trump, who had sought to entirely block questioning on these previous issues if he takes the stand.

Judge Merchan ruled that Trump can be questioned by the DA's office on six determinations from four previous proceedings, including aspects of his New York civil fraud case and the gag order violations there, as well as both verdicts in the E. Jean Carroll cases and the 2018 Trump Foundation case.

Prosecutors had originally asked to question Trump about six different proceedings with 13 total determinations.

Merchan said with his ruling, he has "greatly curtailed" how much prosecutors can discuss the underlying facts of those cases.

"The court cautions the defendant that this Sandoval ruling is a shield, not a sword," Merchan said.

Prosecutors told Judge Merchan that they need 40 minutes for their opening statements.

Defense attorneys told the judge they need 25 minutes.

The judge also announced that court will break at 12:30 p.m. ET today, after a juror had a toothache and got an emergency appointment this afternoon.

Court had already been scheduled to end early today, at 2 p.m. ET, due to the Passover holiday.

Judge Juan Merchan announced there is an issue with Juror No. 9 -- who, according to Merchan, "was concerned about media attention" of the case. According to Merchan, the juror "wasn't 100% sure" they could serve.

Merchan said they would speak to the juror in chambers to "find out what the issue is and see if this juror can continue to serve."

After a brief sidebar, the judge announced: “Juror No. 9 is going to remain with us.”

There are six alternate jurors seated in case any of the 12 jurors cannot serve.

Donald Trump is "not just our former president, he's not just Donald Trump that you've seen on TV," said defense attorney Todd Blanche in his opening statement.

"He's also a man. He's a husband," Blanche said. "He's a father."

Blanche pushed back on the DA's overall allegation that the payments to Trump's attorney Michael Cohen were weren't only payback for Stormy Daniels by using the prosecutor's own words against him.

Blanche noted that Cohen paid $130,000 to Daniels, but that Trump paid back Cohen a total of $420,000. If Trump really was a frugal businessman, as prosecutors said, why would he overpay that money, Blanche asked.

"Ask yourself, would a frugal businessman, a man who pinched his pennies, repay a $130,000 debt to the tune of $420,000?" Blanche asked.

Blanche repeatedly reiterated that Cohen truly was an attorney for Trump and was doing legal work for him, pointing out that Michael Cohen's own email signature noted he was Trump's attorney.

"None of this was a crime," Blanche said, saying the 34 counts against Trump "are really just 34 pieces of paper."