Trump Is Guilty of ‘Numerous’ Felonies, Prosecutor Who Resigned Says

One of the senior Manhattan prosecutors who investigated Donald J. Trump believed that the former president was “guilty of numerous felony violations” and that it was “a grave failure of justice” not to hold him accountable, according to a copy of his resignation letter.

The prosecutor, Mark F. Pomerantz, submitted his resignation last month after the Manhattan district attorney, Alvin Bragg, abruptly stopped pursuing an indictment of Mr. Trump.

Mr. Pomerantz, 70, a prominent former federal prosecutor and white-collar defense lawyer who came out of retirement to work on the Trump investigation, resigned on the same day as Carey R. Dunne, another senior prosecutor leading the inquiry.

Mr. Pomerantz’s Feb. 23 letter, obtained by The New York Times, offers a personal account of his decision to resign and for the first time states explicitly his belief that the office could have convicted the former president. Mr. Bragg’s decision was “contrary to the public interest,” he wrote.

“The team that has been investigating Mr. Trump harbors no doubt about whether he committed crimes — he did,” Mr. Pomerantz wrote.

Mr. Pomerantz and Mr. Dunne planned to charge Mr. Trump with falsifying business records, specifically his annual financial statements — a felony in New York State.

Mr. Bragg’s decision not to pursue charges then — and the resignations that followed — threw the fate of the long-running investigation into serious doubt. If the prosecutors had secured an indictment of Mr. Trump, it would have been the highest-profile case ever brought by the Manhattan district attorney’s office and would have made Mr. Trump the first American president to face criminal charges.

Earlier this month, The Times reported that the investigation unraveled after weeks of escalating disagreement between the veteran prosecutors overseeing the case and the new district attorney. Much of the debate centered on whether the prosecutors could prove that Mr. Trump knowingly falsified the value of his assets on annual financial statements, The Times found, a necessary element to proving the case.

While Mr. Dunne and Mr. Pomerantz were confident that the office could demonstrate that the former president had intended to inflate the value of his golf clubs, hotels and office buildings, Mr. Bragg was not. He balked at pursuing an indictment against Mr. Trump, a decision that shut down Mr. Pomerantz’s and Mr. Dunne’s presentation of evidence to a grand jury and prompted their resignations.

Mr. Bragg has said that his office continues to conduct the investigation. For that reason, Mr. Bragg, a former federal prosecutor and deputy New York State attorney general who became district attorney in January, is barred from commenting on its specifics.

Mr. Bragg’s predecessor, Cyrus R. Vance Jr., had decided in his final days in office to move toward an indictment, leaving Mr. Trump just weeks away from likely…