The federal prosecutor who supervised the investigation of Michael D. Cohen, President Trump’s longtime personal lawyer, has left the government and will be joining the law firm Davis Polk & Wardwell, the firm said.
The former prosecutor, Tatiana R. Martins, 41, ran the public corruption unit in the United States attorney’s office in Manhattan for a year, having previously served as the deputy chief.
Ms. Martins led the team that retried Sheldon Silver, the powerful former Democratic speaker of the New York State Assembly, who was convicted on corruption charges in May after a previous conviction was overturned last year.
The new chief of the corruption unit is expected to be Ms. Martins’s deputy, Russell Capone, 38, who has investigated allegations of graft among police officials and helped to try Norman Seabrook, the former head of the city’s correction officers’ union. After a jury could not reach a verdict in Mr. Seabrook’s trial in November, a mistrial was declared, and he is to be retried this month.
The personnel changes at the prosecutor’s office come under its relatively new head, Geoffrey S. Berman, who was named interim United States attorney in January by Attorney General Jeff Sessions and was formally appointed in April by the Federal District Court in Manhattan. The court acted after Mr. Trump did not nominate anyone to the post and Mr. Berman’s 120-day temporary term was about to expire.
The office’s highest-profile known corruption investigation is of Mr. Cohen’s business dealings. Mr. Berman has been recused from that investigation, which instead was placed under his deputy, Robert S. Khuzami.
Ms. Martins, who was born in Brazil and came to the United States as a child, worked as an associate at Davis Polk before becoming a prosecutor. She joined the United States attorney’s office in 2012. She also investigated Gov. Andrew M. Cuomo’s shutdown of the anti-corruption panel known as the Moreland Commission. (No charges were brought against Mr. Cuomo.) In 2015, she helped win the conviction of Dean G. Skelos, the former Republican State Senate majority leader. His conviction was also overturned on appeal, and he is being retried.
Ms. Martins is returning to Davis Polk as a partner, focusing on white-collar criminal defense matters, the firm said.
