"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.

Deutsche Bank executives courted Donald Trump to attract more business and referrals, viewing the former president as an opportunity to sell services to his family members and other high-net-worth individuals, according to the testimony of former Deutsche Bank managing director Rosemary Vrablic.

"Given the circles this family travels in, we expect to be introduced to the wealthiest people on the planet," Vrablic wrote to colleagues while courting Trump in the early 2010s, according to materials entered into evidence.

Recruiting Trump stemmed from a 2007 effort in the bank to develop a broader commercial real estate financing division for their high-net-worth individuals.

"He would have fit the category of the entrepreneur and investor with a successful track record," Vrablic testified on the stand regarding Trump's profile.

After being introduced to Donald Trump Jr. through Ivanka Trump's now-husband Jared Kushner, Vrablic began pursuing Donald Trump's business.

"We are whale hunting ... Haven't seen him yet. Also maybe Dad will convert like Ivanka did," Vrablic wrote in a 2011 email to a colleague.

"It is a term used when there is a very high-net-worth individual who is a prospect," Vrablic said in explaining why she referred to Trump as a "whale."

Once Trump was on board, leadership from the bank personally courted Trump to do more business with the bank and to connect them to other potential clients. The former CEO of the bank personally met with Trump with the express goal of gaining more deposits from Trump and leveraging Trump's relationships.

CEO Anshu Jain "thought that if Mr. Trump wanted to, there could be additional leverage provided among his world," Vrablic testified.

The effort appeared to work, as the bank made over $3 million in revenue from Trump in 2013, up from only $13,000 in 2011.