Pepper Hamilton L.L.P. announced Thursday that Thomas M. Gallagher, head of the firm's white-collar litigation and investigations practice group, has become chair of the firm, succeeding former FBI Director Louis Freeh, who had reached the end of his two-year term.

The firm had begun a search for Freeh's replacement earlier this year and Gallagher was named chair by the firm's 12-member executive committee in August.

Freeh was seriously injured in an auto accident near his vacation home in Vermont on Aug. 25, well after the succession plan had been set in motion, and he is continuing to recover, the firm said.

"I am honored to be named chair of a firm with such a long and storied history," Gallagher said. He said the firm would continue to focus on its strategic plan to grow and strengthen core practices such as defending drug and medical-device makers in regulatory proceedings and other matters. He said the firm's decisions to open an office in Los Angeles in 2012 and an office in Silicon Valley in northern California were emblematic of its growth strategy.

In a statement, Freeh said: ". . . at the beginning of August I advised the executive committee that I intended to step down as chair and I asked them to plan for my succession. Tom's selection as chair is the result of that process."

Gallagher, 54, who did his undergraduate work at the University of Pennsylvania and obtained his law degree from Villanova University, joined the firm in 2003. Previously, he had been a prosecutor in the U.S. Attorney's Office in Philadelphia.

Freeh merged his Wilmington-based firm, which specialized in in-house investigative and consulting work, with Pepper Hamilton in 2012. In early 2013, he was elected chair of the firm.

Gallagher, who lives in Gladwyne, is a past vice chair of the firm's executive committee. He plans to continue his practice. In the past, he has defended pharmaceutical manufacturers in parallel criminal and civil investigations by federal authorities as well as in state attorney general investigations.

Gallagher also has represented a client in a congressional investigation, conducted internal probes, and represented a lawyer in a criminal case involving federal campaign-finance laws, among many other matters.