Andrew Weissmann, a former U.S. Justice Department official and a top member of Robert Mueller’s special counsel team, is returning to Jenner & Block as co-chairman of the firm’s investigations, compliance and defense practice.

Weissmann had a lead role in winning convictions against Trump campaign officials Paul Manafort and Rick Gates during the Mueller probe. His past prosecutorial targets have included Enron executives and the Genovese crime family, among others.