John Terzaken, co-head of the global antitrust practice at Allen & Overy and head of the Magic Circle firm’s investigations and litigation practice in Washington, D.C., is poised to join Simpson Thacher & Bartlett as a partner in the nation’s capital.

“It’s great opportunity,” Terzaken said. “Simpson Thacher is a terrific firm and I think most compelling to me was to get to work alongside others who do what I’ll call high-end crisis management [in] the fraud, sanctions and securities space.”

Terzaken, who joined Allen & Overy five years ago from the U.S. Department of Justice, has spent his time in private practice representing both international and national clients in government enforcement and litigation matters related to cartel and antitrust violations. Before joining the firm in 2012, Terzaken spent nearly eight years in the Justice Department’s antitrust division.

He first joined Main Justice in 2004 as a trial attorney, eventually rising within the Justice Department to become assistant chief in the national criminal enforcement section. In 2010, Terzaken became director of criminal enforcement in the antitrust division, where he spent the next two years handling some of the largest international cartel investigations.

Terzaken said his move to Simpson Thacher, which in December saw former antitrust leader Kevin Arquit leave its ranks for Weil, Gotshal & Manges, was predicated on the opportunity for him to work with a broader base that has the ability to service clients in the U.S. in the crisis management space.

“They do a lot of work with large corporations,” Terzaken said of his new firm, known for its deep ties to private equity firms and large financial institutions. “In particular working [on] more compliance management type issues where a company has a problem that they need to go in and do an internal investigation about how to remedy it.”

Terzaken, who began his legal career at Morgan, Lewis & Bockius in 2000 before moving on to Ropes & Gray, is just the latest former government official to join the Wall Street firm.

In May, Simpson Thacher brought back former U.S. Securities and Exchange Commission associate general counsel David Blass as an investment funds partner in Washington, D.C. In February, the firm hired Michael Osnato, a former chief of the complex financial instruments unit of the SEC’s enforcement division, as partner in its New York office.

Simpson Thacher did see retired partner William Hinman in Silicon Valley leave earlier this year to head the SEC’s division of corporate finance, while former partner Keith Noreika in Washington, D.C., was tapped by the U.S. Department of the Treasury to take over leadership of the Office of the Comptroller of the Currency.

As for Allen & Overy, the London-based legal giant bolstered its U.S. operations in January by bringing on an energy and commodities team from Cadwalader, Wickersham & Taft in Washington, D.C., as well as adding a finance partner from Ashurst in New York earlier this month.

Terzaken’s new firm, however, is looking forward to his addition.

“[Terzaken] has outstanding experience successfully handling a wide range of high-profile antitrust matters,” said a statement by Jonathan Youngwood, co-chair of Simpson Thacher’s litigation department. “His broad-gauged experience and leadership in both the public and private sectors will be extremely beneficial to our clients and will further add to our talented bench of former enforcement attorneys, prosecutors and trial lawyers from the FTC, DOJ and SEC.”