• Donald Trump said he invoked his Fifth Amendment right to refuse to answer questions by investigators for New York Attorney General Letitia James.
• The scheduled deposition came days after the FBI raided Mar-a-Lago, Trump's Florida home, as part of a criminal probe into White House documents taken there by the former president.
• James is investigating business practices of the Trump Organization.
• Trump's adult children Donald Trump Jr., Eric Trump and Ivanka Trump previously appeared for depositions in James' probe.

Former President Donald Trump invoked his Fifth Amendment right more than 440 times Wednesday in refusing to answer questions at a deposition by lawyers for New York Attorney General Letitia James, who is investigating the Trump Organization's business practices, a source with knowledge of the session told NBC News.

Shortly after arriving at that court-ordered interview under oath at James' offices in lower Manhattan, Trump released an email saying he would not answer any questions given the Fifth Amendment right barring people from being compelled to make self-incriminating statements.

Trump answered just one question — his name — and then cited the Fifth on every other question he was asked during the deposition, his lawyer Ronald Fischetti told NBC News.

Trump also read aloud a statement in which he called James' probe "the greatest witch hunt in the history of our country," and accused the Democratic attorney general of "openly campaigning on a policy of destroying me," Fischetti said.

James was there for about half of the total four-hour session, according to Fischetti.

Trump's lawyer said that Kevin Wallace, an attorney in James' office, asked Trump about the valuations of various real estate assets, including golf clubs, his signing of documents in connection with mortgages and loans, and the size of his apartment. Fischetti described the mood in the room as polite and not tense.

Trump's refusal to answer questions was legal, and had been anticipated in the judicial order mandating his attendance at the deposition. But it could harm his chances of prevailing against James in any civil litigation she files in connection with her probe.

James is focused on allegations that the Trump Organization improperly reported the stated valuations of some of its real estate assets for financial gain, in the form of better terms on loans and insurance, and tax benefits.

"I once asked, 'If you're innocent, why are you taking the Fifth Amendment?' Now I know the answer to that question," Trump said in the emailed statement after he arrived at the deposition, which claimed James is a renegade prosecutor with a vendetta against him and his company.

"When your family, your company, and all the people in your orbit have become the targets of an unfounded, politically motivated Witch Hunt supported by lawyers, prosecutors, and the Fake News Media, you have no choice," Trump said.

"Accordingly, under the advice of my counsel and for all of the above reasons, I declined to answer the questions under the rights and privileges afforded to every citizen under the United States Constitution," he said.

In 2016 Trump suggested that people who cite the Fifth Amendment when being questioned are guilty of something.

A spokesperson for James said in a statement late Wednesday afternoon, "While we will not comment on specific details, we can confirm that today, our office conducted a deposition of former president Donald Trump."

"Attorney General Letitia James took part in the deposition during which Mr. Trump invoked his Fifth Amendment right against self-incrimination," the spokesperson said.

"Attorney General James will pursue the facts and the law wherever they may lead. Our investigation continues."

Trump's deposition came two days after the FBI, in an unrelated criminal investigation, raided his home at the Mar-a-Lago club in Palm Beach, Florida, and seized what his attorney has said were about a dozen boxes of documents.

That search was related to an ongoing investigation into whether laws were broken when boxes of White House records — which included some documents marked as classified — ended up at Mar-a-Lago instead of the National Archives.

A Manhattan Supreme Court judge in his February ruling ordering Trump and two of his adult children to submit to questioning by James' team had noted they would "have the right to refuse to answer any questions that they claim might incriminate them."

Judge Arthur Engoron also wrote that if the Trumps invoked the Fifth Amendment, their refusal to answer questions cannot be used against them in a criminal prosecution.

But Engoron went on to note that a jury in a civil case is allowed to draw "a negative inference" when a party to the case "invokes that right against self-incrimination." In other words, James could argue to a jury that it should assume Trump has conceded her claims against him by refusing to answer her questions.

The Trumps had asked Engoron to block the subpoenas, or at least stay their enforcement until the conclusion of a parallel criminal probe of the Trump Organization by the Manhattan District Attorney's Office.

Trump has denied wrongdoing in all the pending probes involving him.

Trump said he decided he had "absolutely no choice" but to plead the Fifth in James' deposition following the FBI raid at Mar-a-Lago "because the current Administration and many prosecutors in this Country have lost all moral and ethical bounds of decency."

In a post on his social media platform early Wednesday, he also accused James, who is Black, of being "racist," a charge he has also previously leveled at her and two other Black prosecutors who are separately investigating him.

Trump and two of his adult children, Donald Trump Jr. and Ivanka Trump, for months had resisted complying with subpoenas from James demanding their testimony under oath for her probe.

But after failing in court efforts to block those subpoenas, Donald Jr. and Ivanka answered questions from James' investigators last week, NBC previously reported. Donald Jr. runs the Trump Organization with his brother Eric Trump, and Ivanka is a former Trump Organization executive who served as a senior White House advisor during her father's administration.

Eric Trump invoked his Fifth Amendment right more than 500 times when he was questioned under oath in the probe in October 2020, according to a court filing in January.

While campaigning for president in 2016, Trump in a speech in Iowa blasted some staffers of his Democratic opponent, former Secretary of State Hillary Clinton, for invoking the Fifth Amendment when they were questioned by a House select committee investigating the attack on American diplomatic facilities in Benghazi, Libya.

"So there are five people taking the Fifth Amendment. Like you see on the mob, right? You see the mob takes the Fifth. If you're innocent why are you taking the Fifth Amendment?" Trump asked at that time.

Trump's refusal to testify Wednesday made even more dramatic a week that began with what is believed to be the first-ever search of a former president's residence by federal law enforcement agents as part of a criminal probe.

Monday's raid sparked a political firestorm, with Republicans harshly criticizing the FBI — which is led by Director Chris Wray, a Trump appointee — and demanding answers about the reasons for it from Attorney General Merrick Garland, a nominee of President Joe Biden.

The Department of Justice has not revealed details about the search warrant that the FBI executed.

Legal experts say Trump's lawyers are in possession of a copy of that search warrant and that they can disclose its contents if they choose. The warrant and a related affidavit in support of it would detail what the FBI was looking for and how the agency believed there was probable cause that a crime or crimes had been committed that related to that evidence.

But Trump's team does not plan to release a copy of the warrant, a source close to Trump told NBC News.

Trump and his family and business are the focus of multiple active investigations at the state and federal level.

In addition to the probe of records at Mar-a-Lago, the Justice Department is reportedly investigating events leading to the Jan. 6, 2021, Capitol riot by thousands of Trump supporters, who for hours disrupted the confirmation of Biden's electoral victory by a joint session of Congress.

The Manhattan District Attorney's Office last year charged the Trump Organization and its chief financial officer with a criminal scheme to evade taxes in compensation paid to executives.

In Georgia, a special state grand jury is investigating possible criminal efforts by Trump and others to interfere in the 2020 presidential election in that state as part of a nationwide push to overturn Biden's victory in the race for the White House.

On Tuesday, a federal appeals court in Washington, D.C., upheld a lower court ruling dismissing an effort by Trump to block the House Ways and Means Committee from obtaining several years of his federal income tax returns and those of a number of Trump business entities from the Treasury Department.

The committee has said it wants those records to review how the IRS is complying with a law that requires annual audits of the tax returns of sitting presidents.