Judge Merchan told jurors that Michael Cohen is an "accomplice" to the alleged crime, so the jury cannot convict Trump on Cohen's testimony alone.

Even if they believe Michael Cohen, they need to rely on evidence corroborating his testimony, Merchan said.

Trump, at the defense table, appeared to perk up just a bit at this, looking up at Merchan as he delivered this information to the jury.

Judge Merchan told the jury that they have the ultimate authority in determining the truthfulness of a witness' testimony -- an instruction that might come in handy given the emphasis that defense lawyers placed on Michael Cohen's testimony, which they say includes lies.

"You will alone determine the truthfully and the accuracy of the testimony of each witness," Merchan said.

He added that the jury could either disregard the testimony of an untruthful witness entirely, or disregard part of it.

"There is no particular formula" to determine credibility, Merchan said.

"You may consider whether the witness has any interest in the outcome of the case," he said -- another matter that might weigh on jurors' minds.

"You may consider whether a witness did have, or did not have, a motive to lie," the judge said.

Trump's attorney had told the jury Cohen had an "axe to grind" against his former boss. Prosecutors partially conceded that Cohen had a motive, acknowledging that, to date, he is the only one who suffered any consequences from the matter at hand.

Trump, at the defense table, appeared to look over to the jury and offer a bit of a closed-mouth grin.

Judge Merchan instructed the jury that they cannot hold Trump's not testifying against him.

"Defendant is not required to prove that he is not guilty," he said.

"The defendant is not required to prove or disprove anything," said the judge.

Judge Merchan told the jury that they should not speculate about the sentence or punishment in the case.

"It will be my responsibility to impose an appropriate sentence," Merchan said.

The judge also had to advise the jury about this yesterday after defense lawyer Todd Blanche argued that the jury "cannot send somebody to prison" based on Michael Cohen's testimony.

The jury appears to be laser focused on Merchan during the charge. Half of the jurors appear to be taking notes.

Prosecutor Josh Steinglass laid out the DA's case for why Trump should be found guilty of falsifying records, even if he didn't pen them himself and just directed it to be done.

"Tarasoff may be doing the typing, but the defendant is causing the false business records," Steinglass said, referring to Trump Organization accountant Deborah Tarasoff.

Steinglass said Trump "doesn't want to leave a paper trail" and instead would "have his lackeys do it."

"If Trump didn't know about the scheme, why was he just signing the checks 'for services rendered' for $35,000 each month?" Steinglass asked.

"Does he call Cohen and say, 'Why'd I pay you $35000 for nothing?' No. He just signs it. Every month. He never once picks up the phone, he never once makes further inquiry," said Steinglass.

"Despite his frugality and attention to detail, the defendant didn't ask any questions. Because he already knew the answers."