"One thing I know a lot about is the legal definition of fraud," Justice Arthur Engeron said as he gaveled court into session prior to the start of opening statements.

Engoron opened the proceedings after allowing cameras in to document the scene in the courtroom: Trump, arms folded, flanked by his legal team; Engeron on the bench; and throngs of reporters and spectators in the gallery.

"I've promised to do my best despite my lame attempts at humor," Engeron said in a brief opening statement. "I take my job very seriously."

The trial is expected to last through Dec. 22, Engeron said, and suggested he would attempt to keep a low profile after today.

"For the next three months, I hope the only words I will mutter are 'Sustained,' 'Overruled,' and 'Let's take a 10-minute break,'" he said.

Opening statements are underway in former President Trump's $250 million fraud trial.

Trump is seated between his attorneys Clifford Robert, Alina Habba and Christopher Kise.

Trump and his co-defendants face a bench trial, meaning that the sole arbiter of the case is Judge Arthur Engoron instead of a jury.

Former President Trump has taken a seat in the courtroom for the start of the trial.

"The crime is against me," he told reporters outside the courtroom before he made his way inside.

He denounced the case in now-familiar terms, criticizing state Attorney General Letitia James as she sat inside the courtroom.

Trump also accused Judge Arthur Engoron of failing to account for the full value of his real estate portfolio, asserting his Mar-a-Lago estate is worth "50 to 100 times more" than the judge's decision for partial summary judgment said last week.

"We have other properties, the same thing. So he devalued everything," Trump said. "We have among the greatest properties in the world. and I have to go through this for political reasons."

Engoron decided Trump's statements of financial condition were fraudulent, but Trump said, "We have a clause in the contract that says, essentially, buyer beware."

Former President Trump, speaking to reporters on his arrival at the lower Manhattan courthouse, said the trial is a witch hunt resulting from his standing in the presidential polls.

"This is a continuation of the greatest political witch hunt of all time," he told reporters outside the courtroom.

Trump said he is innocent of the accusations and that his portfolio has a much higher value than what the attorney general alleges.

The second day of testimony from the defense's expert accounting witness prompted an argument between attorneys for the two sides over the basic question of what the case is about -- leading defense lawyers to make their fourth unsuccessful request for a directed verdict to end the trial.

The arguments came toward the end of direct testimony by accounting expert defense Eli Bartov, who asserted the New York attorney general's case lacked merit because there was no evidence of any fraud on Trump's statements of financial condition, and that any errors about the values of Trump's properties were unintentional and therefore immaterial.

When the defense attempted to question Bartov about those values, state attorneys objected -- prompting defense attorney Christopher Kise to leap from his seat.

"If they don't call anyone to dispute our values, how have they proven their case?" Kise said.

Judge Arthur Engoron, in a pretrial ruling, already decided that Trump conducted a decade's worth of business using fraudulent financial statements, and state attorney Kevin Wallace suggested that Bartov's findings do not change those findings.

"You can't use false statements in business. That's what the summary judgment decision is all about. I think it is pretty much what the rest of this case is about," Engoron said in response to Kise's question.

Kise argued that if the attorney general doesn't prove what Trump's asset values should have been, the case is a "completely rudderless ship" that needs to be "moored to some sort of standard."

"You can't just say it's a misstatement because you feel like it," Kise argued.

"The standard is truth," Engoron responded.

The exchange prompted Trump's legal spokesperson, Alina Habba, to make the defense's fourth motion for a directed verdict, arguing that Engoron is "wasting our time" if he won't consider their expert testimony.

"They have not proven their case. They haven't," Habba said in her request for a directed verdict.

"Denied," Engoron said within seconds of the request, without hearing a response from lawyers for the New York attorney general.