Manhattan District Attorney Cyrus Vance, Jr. has announced that he will not seek re-election for a fourth term in 2021.

“Representing the People of New York during this pivotal era for our city and our justice system has been the privilege of a lifetime," Vance said in a statement. The 66-year-old was elected in 2009, replacing longtime D.A. Robert Morgenthau,

Vance is currently in the middle of investigating the finances of former President Donald Trump, and his successor will take over that probe, and preside over the country's most prominent prosecutor's office.

Vance's announcement was not a surprise, given that he had not raised any campaign funds. But he told the New Yorker, which first reported his decision, "It turned out to be tougher than I thought it would be," referring to leading the high-profile office. "There’s nothing worse than a politician who doesn’t know when to leave," he added.

In his statement, Vance touted accomplishments like making reforms that led to reductions in our "criminal justice footprint and the inequities that underlie unnecessary prosecutions," noting that his office's total prosecutions fell by 58%, though critics assert the office has continued low-levels prosecution of Black and brown New Yorkers.

There are eight candidates running for the position, many of them promising not to focus on those kind of prosecutions (disorderly conduct, petit larceny and criminal possession of a controlled substance in the seventh degree were the most common misdemeanor convictions in 2020).

READ MORE: Who is running for Manhattan D.A.? ALSO: What will they refuse to prosecute?

Vance also cited using $250 million seized in investigations of major banks to fund dozens of community organizations in the Criminal Justice Investment Initiative, as well as the conviction of film producer Harvey Weinstein for rape and sexual assault. However, the Weinstein conviction came five years after his office decided not to press charges after the producer, who had been arrested by police for groping a model. Former police investigators said they disagreed with Vance's actions.

His office also agreed to a 2016 plea deal with a gynecologist who had been accused of sexually abusing patients—a deal that allowed Dr. Robert Hadden to escape prison time and a Level 2 sexual offender status—only to reopen the investigation after survivors, including mayoral candidate Andrew Yang's wife Evelyn Yang—came forward in 2020.

Other high-profile sexual abuse cases also faced issues under Vance's term. In spite of a conviction in Florida, his team argued that Jeffrey Epstein should not be considered a top-level sexual offender, and eventually the office had to ask a judge to drop rape charges against IMF head Dominique Strauss Kahn in 2011.

For its investigation into Trump's finances, Vance's office recently hired former federal prosecutor Mark Pomerantz, who previously headed the criminal division in the Southern District of New York, noting his "deep experience investigating and defending white-collar and organized crime cases." Also, Trump's ex-attorney Michael Cohen said earlier this week he would be meeting with the Manhattan's D.A.'s office for a seventh time.

Former U.S. Attorney Preet Bharara told the New Yorker, "All the signals indicate that there’s a belief on the part of that office that there’s a good chance of a charge," but also warned, "no one should be under the illusion that this is easy or a slam-dunk case."