Jillian Berman, a former federal prosecutor who worked at Levine Lee for more than five years, has moved to Lankler Siffert & Wohl, drawn by the opportunity to work again with a longtime mentor.

Berman, who joined Lankler on Monday as a partner, had nothing but praise for her former colleagues at Levine Lee, a white-collar and commercial litigation boutique. But she said the opportunity to work at Lankler was “too good to pass up.” With her move, she will be joining Dan Gitner, who supervised her during her days as a newbie prosecutor at the U.S. Attorney's Office for the Southern District of New York.

“I've had a wonderful time at Levine Lee and I have incredible respect for the firm and people and attorneys there,” she said. “Lankler is a firm that I've held in high regard for a long, long time … in part because Dan Gitner, who is a partner here, was my mentor and general crimes chief at the U.S. Attorney's Office.”

Much of her work these days is confidential, performed for clients who are individuals or privately held companies. Berman said her clients range from witnesses to subjects or targets of an investigation in matters in which the Justice Department or another federal regulator is normally involved.

At Levine Lee, where she was a partner, Berman said her defense work for Robert Stewart, who was charged with trading on information passed along to him from his investment-banker son Sean Stewart, left an impression. Robert Stewart pleaded guilty and was sentenced to four years' probation; Sean Stewart was convicted, but his conviction was recently overturned on appeal.

“That case was complicated, rewarding, challenging on a number of levels—both legal issues presented and personal dynamics—and [was] one of the first charged cases I've had on the defense side,” she said.

Over the years, court records indicate that Berman worked at various points defending Gavin Black, a former Deutsche Bank trader charged with Libor-rigging, and Anthony Blumberg, the CEO of ConvergEx Global Markets. Lankler said in a statement that her clients include “corporate executives, portfolio managers and finance professionals, law firms, broker-dealers, real estate firms and other companies.”

As a prosecutor from 2004 to 2013, Berman worked on several insider trading cases, including the prosecution of tipper Roomy Khan and one of the beneficiaries of her intelligence, Doug Whitman, as well as on the case against Wesley Wang, another of Whitman's tippers. She also prosecuted Berton Hochfeld, who was convicted of stealing $2 million from investors.

Contacted for comment, Seth Levine of Levine Lee said, “We wish Jillian all the best in future and fully expect that we will continue to work together.”