William Johnson and Dixie Johnson, two leaders of Fried, Frank, Harris, Shriver & Jacobson’s white-collar defense and securities enforcement practice, are leaving to join King & Spalding.

William Johnson, 47, a Law Journal columnist based in New York, joined Fried Frank in 2009. He served as a prosecutor at the U.S. Attorney’s Office for the Southern District where he was chief of the Securities and Commodities Fraud Task Force and oversaw the investigation and prosecution of cases including Galleon Group/Raj Rajaratnam, Bernard Madoff, Marc Dreier and Refco. He also served as an attorney at the SEC.

Since joining Fried Frank in 1986, Dixie Johnson, in Washington, D.C., has represented businesses and individuals in government securities investigations. She counsels clients on regulatory and disclosure obligations and conducts internal investigations.

Christopher Wray, leader of King & Spalding’s government investigations practice, said the firm been seeking a New York attorney with William Johnson’s background for a while. “I do not think all former prosecutors are created alike. It’s a real question about not just quantity of experience but quality of experience,” Wray said.

He said William Johnson and Dixie Johnson, who are not related, bring to the firm “a deep reservoir” of experience with sensitive investigations.

“This is a space in which an awful lot of happens behind the scenes, quietly in high stakes discussions and conference rooms,” he said. “There’s a premium on judgment.”

“We intend to continue to grow in this space,” he said. “It’s a reflection of what’s going on in the world these days as government and internal investigations are unfortunately a fact of life for most big companies.”

King & Spalding, an Atlanta founded firm, has more than 100 lawyers in New York.

David Greenwald and Valerie Ford Jacob, co-chairs of Fried Frank, said the firm does not comment on “specific personnel moves” but “wish all former colleagues well in their future endeavors.”

They said the firm looked forward to naming a number of new partners. “We are pleased with the Firm’s performance, which has increased substantially from the end of last year and includes significant assignments in all of our key practice areas,” they said.