Tax returns can be crucial evidence for proving that a defendant misstated the value of assets, said Daniel R. Alonso, who was Mr. Vance’s top deputy from 2010 to 2014 and is now in private practice. “Tax returns are an obvious place to look because of the precision required by tax authorities,” he said.
The district attorney’s investigation has been proceeding in fits and starts since it began in the summer of 2018. Almost immediately, Mr. Vance paused the inquiry at the request of the United States attorney’s office in Manhattan, which had prosecuted Mr. Cohen and was investigating whether others at the Trump Organization had committed crimes in the course of arranging the hush-money payments.
In early 2019, Mr. Cohen testified on Capitol Hill that Mr. Trump had inflated the value of his assets in order at times to obtain financing from Deutsche Bank, including in 2014 when he bid unsuccessfully for the Buffalo Bills football team. Mr. Cohen also told federal prosecutors in Manhattan about insurance claims the Trump Organization had filed that he believed had been inflated.
Last summer, after federal prosecutors concluded their investigation of the hush-money payments without bringing additional charges, Mr. Vance’s office resumed its inquiry. In August 2019, the office served a subpoena on Mazars, seeking the president’s tax returns and other financial records going back to 2011.
Mr. Trump filed a lawsuit last September seeking to block Mazars from complying. The case is still being litigated nearly a year later, even after the Supreme Court’s ruling last month affirming Mr. Vance’s right to criminally investigate the president. The justices said that Mr. Trump could go back to the lower court, where he first sued, and raise other objections to the subpoena.
Shortly after Mr. Trump filed his suit last year, Mr. Vance’s office provided the judge who has been overseeing the case, Victor Marrero, a two-page summary of its secret grand jury investigation, which was not made available to the public or to Mr. Trump. Days later, at a hearing in federal court in Manhattan, Judge Marrero said the inquiry “clearly is very complex” and “involves a lot of parties, extends over many, many years.”
While Deutsche Bank has been cooperating with prosecutors, Mr. Vance’s office made it clear to Judge Marrero last month that its inquiry had been stalled without the tax returns.