The confirmation of a former aide to Attorney General Eric Holder to the U.S. Court of Appeals for the Armed Forces may be in peril over his response to questions posed by Arizona Sen. John McCain about his knowledge of Operation Fast and Furious.

Kevin Ohlson, who worked as Holder’s chief of staff from January 2009 to January 2011, faces a confirmation hearing on Thursday for the post. The panel with jurisdiction is the Senate Armed Services Committee, of which McCain is the ranking Republican and Sen. Carl Levin, D-Mich., is chairman.