The No. 2 official at the Justice Department says he is leaving to return to private practice.
David Ogden, a prominent Washington lawyer, is headed back to his former firm, WilmerHale.
As the deputy to Attorney General Eric Holder, Ogden oversaw the crackdown on the Mexican drug cartels and coordinated the work of various law enforcement agencies that work under the Justice Department.
Ogden has been the Deputy Attorney General less than a year, and plans to continue in the position until Feb. 5.
In a statement, Ogden said he was leaving because he had helped put the Justice Department on the right path for the Obama administration, starting with his work on the transition team.