Veteran trial lawyer Beth Wilkinson is helping guide U.S. District Judge Emmet Sullivan as a federal appeals court questions his plan to probe the U.S. Justice Department’s decision to dismiss the case against former Trump national security adviser Michael Flynn despite his admission he lied to the FBI.

Sullivan refused to immediately dismiss the charge against Flynn, a retired Army general who served for just weeks in Trump’s White House, and the U.S. Court of Appeals for the D.C. Circuit is now weighing whether the longtime Washington federal trial judge overstepped his authority.