In a rare step that adds to this criminal case’s already unusual path, U.S. District Judge Emmet G. Sullivan has retained Beth Wilkinson to represent him in defending his decision to a federal appeals court in Washington, according to a person familiar with the hire who spoke on the condition of anonymity because of the sensitivity of the matter. The U.S. District Court of Appeals for the District of Columbia Circuit is now examining the judge’s actions and the larger case against Flynn after lawyers for President Trump’s former national security adviser asked the court to force Sullivan to toss Flynn’s guilty plea.

Wilkinson, known for her top-notch legal skills and get-results style, is expected to file a notice with the court in the coming week about representing the judge. She declined to comment when reached Friday evening. Sullivan also declined to comment through his office.

A federal judge doesn’t typically hire private counsel to respond to an appeals court, and yet so much about Flynn’s case has been a departure from the norm. A defendant doesn’t normally plead guilty under oath and then try to withdraw that admission, as Flynn did. The Justice Department almost never drops a case once it has essentially won a conviction, a signed guilty plea, as Attorney General William P. Barr ordered earlier this month.