Cyrus R. Vance Jr., the Manhattan district attorney leading a criminal investigation against former president Donald Trump and his business dealings, will retire from the office at the end of this year, he announced Friday, intensifying the race to replace him and leaving questions about the future of his open investigation of the former president.

In a memo to his staff, Vance said he would not seek reelection to a fourth term as Manhattan’s top prosecutor, emphasizing that he has known since he was sworn in as district attorney in 2010 that he did not want to serve “for decades” like his predecessors.

“I said that this wouldn’t be a ‘forever job’ for me or even my last job, although the fact is, serving the People of New York is the best job and biggest honor I’ll ever have,” Vance wrote. “Instead, I said I would give it my all for two or three terms, then begin a new chapter in my life and open the pathway for new leadership in the D.A.’s Office. I believed then — and I believe now — that change is a fundamentally good thing for any institution.”

Since 2018, Vance’s office has been investigating potential financial crimes and tax fraud at the Trump Organization, including whether the company manipulated property values of certain assets to gain tax advantages. Last month, Vance’s prosecutors won a significant victory in obtaining Trump’s tax returns and other financial information, despite the former president’s attempts to block them from being released.

Representatives for the Trump Organization did not respond to requests for comment Saturday.

The Manhattan District Attorney's Office has taken possession of former president Donald Trump's tax returns, officials said Feb. 25. (Reuters)

In his announcement Friday, Vance did not specifically address the ongoing investigation into the Trump Organization, though he emphasized multiple times that the work of his prosecutors would continue in general.

“Over the next nine months we’ll work harder than ever to support New Yorkers and their communities, and to move justice forward in court cases large and small,” Vance said in a statement.

The New Yorker’s Jane Mayer recently reported that Vance’s office had “dramatically” intensified its investigation since Trump left office in January, and that Vance will probably be done with the fact-finding portion before he steps down. In December, the district attorney’s office retained forensic accounting experts to comb through Trump’s financial records, another indication the investigation was escalating.

Still, the next district attorney will probably assume the reins of the unprecedented case, including any trial of the former president. Questions about how they would handle the investigation have repeatedly been asked of the eight candidates running to replace Vance as district attorney.

Many of the candidates have said they would seek to reform the office, criticizing Vance for being light on those who are wealthy and well-connected — most notably his decision in 2015 not to press charges against now-disgraced Hollywood film producer Harvey Weinstein. Three years later, as the #MeToo movement swept the country, Vance announced that a grand jury had indicted Weinstein on rape and criminal sexual act charges.

Perhaps seeking to deflect criticisms on those fronts, Vance’s office touted “some of the most high-profile and consequential courtroom victories in recent history, including Trump v. Vance and People v. Weinstein.

All eight candidates running to replace Vance — Tahanie Aboushi, Alvin Bragg, Liz Crotty, Tali Farhadian Weinstein, Diana Florence, Lucy Lang, Eliza Orlins and Dan Quart — are Democrats. Shortly after Vance officially announced he would not seek reelection, several cheered his decision — some harshly criticizing Vance’s record and others more broadly stating that it was an opportunity for the district attorney’s office to be “reformed and reimagined.”

Shayna Jacobs and David A. Fahrenthold contributed to this report.