"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.

State attorney Kevin Wallace, challenging the testimony of an expert witness for the defense, angrily argued that Trump used fraudulent means to gain access to favorable loan rates through Deutsche Bank's private wealth management division.

The exchange came during Wallace's cross-examination of defense expert Robert Unell, who disputed the state's claim that Trump's alleged misstatements cost lenders $168 million in lost interest because, Unell said, the loan rates the state used in their calculation were higher than the rates Trump was entitled to when he used a personal guarantee as a private wealth client.

"Once you are in the private bank, you are in this sort of rarified air, and you get access to these rates ... it is a flawed premise to say you have to compare it to the outside air," argued Trump attorney Chris Kise after Judge Arthur Engoron removed Unell from the courtroom so the attorneys could hash out the permissibility of Wallace's argument.

Shouting at Kise for repeatedly making lengthy objections, Wallace argued that Trump would have not qualified for the private bank rates had he not fraudulently overstated his assets.

"The court has found that Mr. Trump committed fraud," Wallace said. "To get into the private wealth group, he committed fraud."

"He lied to the private wealth group to get these loans. Therefore, we are looking at what the interest rate would have been had he not had access to the group he lied to," Wallace said of the state's calculation.

Overruling Kise's objection, Engoron said that he supported Wallace's theory.

"I think his explanation is correct," Engoron said.