Donald Trump Jr. struggled to answer questions when pressed about why former Trump Organization CFO Allen Weisselberg departed the family's firm.

"Because some legal issues he got himself into," Trump Jr. said, declining to offer specifics about Weisselberg's guilty plea on tax evasion charges last year.

Previously giving lengthy answers to questions about his background and even smiling with the judge, Trump Jr. appeared tense on the witness stand as he answered questions about Weisselberg.

"The specific event was he was indicted," Trump Jr. said.

He added that when began working for the Trump Organization as an executive vice president in the 2010s, Weisselberg outranked him. Trump Jr. would seek Weisselberg's approval for certain business decisions such as refinancing loans.

"Who is above you in your role as an executive vice president in the Trump Organization?" state attorney Colleen Faherty asked.

"Obviously I would have reported to my father in that period of time … people like Allen Weisselberg would have still been senior to me," Trump Jr. said of that time period.

Trump Jr. said he gained more responsibility in 2016 when his father became president and he was named a trustee of his father's revocable trust. He said that he, Weisselberg and his brother Eric Trump became a kind of triumvirate running the Trump Organization.

"We stopped reporting to my father on decisions involving the business," Trump Jr. said.

That relationship broke down once Weisselberg got himself into "legal issues," Trump Jr. said. He testified that he could not recall the circumstances of Weisselberg's exit, including the multimillion-dollar severance deal that Weisselberg received, which Weisselberg faced questions about during his own testimony earlier this month.

"I have no knowledge of the specifics of how it happened. He is no longer working at the Trump Organization," Trump Jr. said of the former CFO.

"Sounds very exciting, but no," Donald Trump Jr. answered to a state attorney's question about whether he knows about accounting certifications, professional organizations, or accounting standards other than GAAP, which stands for "Generally Accepted Accounting Principles."

"I know nothing about GAAP," Trump Jr. said, adding, "I leave it to my CPAs."

"I'm a real estate broker," Trump Jr. said as he introduced himself on the witness stand. He testified that he began working in the family real estate business "right after 9/11," working on Trump Park Avenue and the former Sun Times building in Chicago.

State attorney Colleen Faherty tried to pressed him on his lack of accounting knowledge, prompting several objections from the defense.

Judge Engoron sustained the objections and admonished Faherty against asking negative questions.

Assistant New York Attorney General Colleen Faherty will start off the direct examination of Donald Trump Jr.

Faherty is familiar with questioning high-stakes witnesses, having led the direct examination of former Trump attorney Michael Cohen last week.

Her quick objections during Cohen's cross-examination led Trump attorney Alina Habba to accuse Faherty of trying to "throw off" her game.

A seven-year veteran of the New York attorney general's office and a former criminal defense attorney, Faherty has been a vocal presence in the courtroom since the start of the trial.

Her willingness to spar with Trump lawyer Chris Kise previously led to some heated exchanges in court, such as a sidebar when Faherty demanded Kise "be more respectful."

"No," Kise responded.

"That was rude," Faherty replied.

Donald Trump Jr. has taken the stand, where he will be the first of the former president's children to testify.

Before taking the stand, Trump Jr. sat while news photographers snapped pictures.

"I should've worn makeup," he quipped.

The New York attorney general's civil fraud complaint against former President Trump lacks merit, a defense expert in accounting testified.

"My main finding is that there is no evidence whatsoever for any accounting fraud," New York University professor Eli Bartov said. "My analysis shows the statements of financial condition for all the years were not materially misstated."

Bartov's testimony bolstered the defense's contention that non-audited financial statements, like Trump's, are unreliable and represent only a first step in analysis.

"You cannot use the raw numbers in the statements as the basis for making decisions," Bartov said. "If you do that, you are likely to reach the wrong decision."

Judge Engoron asked Bartov whether the attorney general's complaint had no merit.

"This is absolutely my opinion," Bartov replied.

"And why is that?" defense attorney Jesus Suarez jumped in to ask.

"There is not a single reference to a specific provision of GAAP that was violated," Bartov said, referring to the generally accepted accounting principles." "If you allege there was an accounting violation, they have to tell us what provision was violated."

State attorneys objected to the relevance of Bartov's opinion, but Judge Engoron denied the objection.