(CNN) Attorney General Jeff Sessions has tapped Justice Department official Zachary Terwilliger to serve as US attorney for the Eastern District of Virginia, he announced Thursday.

Terwilliger has been serving as associate deputy attorney general and chief of staff under Deputy Attorney General Rod Rosenstein -- the number two at the department who is overseeing the Russia investigation.

Sources told CNN, however, that Terwilliger was not involved in the Russia probe, and instead has been focused on affirmative department priorities, including combating violent crime, MS-13, and management of the department.

"Zach Terwilliger has a strong record that any prosecutor would be proud of," Sessions said in a statement. "He rose through the ranks in the Eastern District of Virginia, from summer intern to Assistant United States Attorney who made a name for himself successfully prosecuting MS-13 members, Bloods members, and firearm offenders and putting them behind bars."

A career federal prosecutor by training, Terwilliger will now be tasked with leading one of the most a high-profile jurisdictions in the nation, handling terrorism and espionage cases, but also where former Trump campaign chairman Paul Manafort faces criminal charges.

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