David Siegal, who has co-chaired Haynes and Boone's government enforcement and litigation practice for several years, has joined Mintz, Levin, Cohn, Ferris, Glovsky and Popeo as a New York member.

Siegal is best known for obtaining a high-profile defense victory for private equity financier Benjamin Wey in a securities fraud and money laundering case. The Justice Department and the Securities and Exchange Commission voluntarily dismissed their cases against Wey, after a judge suppressed evidence based on deficient warrants.

Siegal, who joined Mintz Levin on Monday, previously served for nine years as an assistant U.S. attorney in the Southern District of New York, including as a member of the office's Securities and Commodities Fraud Task Force. He joined Dallas-based Haynes and Boone in 2009 after leaving the government.

In more than 25 years of practice, Siegal has tried 20 federal criminal and civil cases, almost all to juries that returned verdicts, Mintz Levin said. He represents individuals and companies in government enforcement investigations and actions, including those in financial services, manufacturing, sports management and pharmaceutical industries. He currently represents broker Roman Sledziejowski in a securities fraud case scheduled for a June trial in Texas.

Siegal, 50, said he anticipates his clients to join him at the Boston-founded firm.

“My client relationships are the type where the client and his lawyers develop a personal, strong bond in high-stakes, often high-stress situations,” he said.

Siegal said he was “attracted to the size and quality” of Mintz Levin's East Coast white-collar defense practice. At his prior firm, he said he was the only white-collar defense-focused practitioner in New York.

Mintz Levin's strong financial year was another factor in his decision to move, he said. The firm saw a third consecutive year of record financial growth last year.