O'Melveny & Myers has hired Benjamin Singer, a former senior prosecutor in the Justice Department, as a partner in Washington, D.C.

Singer worked his last day May 18 as chief of the securities and financial fraud unit in the DOJ's Criminal Division. He will start as a partner in O'Melveny's white-collar defense and corporate investigations practice on July 1.

After nine years at the Justice Department, Singer said it was important to him to join a firm with a culture he respects and appreciates. “I think it's a once-in-a-lifetime opportunity,” Singer said of his new firm.

Singer said he thought the time was right to leave the Justice Department because he accomplished the goals he set out to achieve when he got there—running big investigations, doing trial work, and being a leader with the opportunity to help set department policy and mentor younger lawyers.

Singer oversaw a team of 50 federal prosecutors investigating complex fraud cases. (He said he did not expect any of his colleagues to follow him “immediately.”) He played a key role in the government's investigation of Volkswagen for allegedly evading U.S. emissions standards.

Singer also worked as head of the health care fraud unit, leading a team that prosecuted Medicare fraud, and he supervised the creation of Medicare Fraud Strike Forces in Detroit, Dallas and Tampa.

He is the second prominent prosecutor to move to O'Melveny this year, following Nicole Argentieri, former Eastern District of New York public integrity section chief, who joined the firm in New York in April.

Singer declined to answer questions regarding the former head of the Criminal Division's fraud section, Andrew Weissmann, one of special counsel Robert Mueller's first hires and a top lieutenant in the ongoing probe.

Weissmann's tenure at the DOJ is facing new scrutiny following a Monday night court filing from attorneys for Paul Manafort, President Donald Trump's former campaign chairman. Manafort's attorneys are pushing a federal judge for a hearing involving the leak of confidential grand jury information and pointed to a meeting Weissmann reportedly attended with The Associated Press in April 2017, when Weissmann still served at the Justice Department.