Rod Rosenstein, the embattled U.S. deputy attorney general, is planning to argue before the U.S. Supreme Court on April 23, representing the United States in a criminal sentencing case.

A Justice Department spokeswoman confirmed on Friday that Rosenstein will argue in Chavez-Mena v. United States, a test of how much justification judges have to offer when deciding not to reduce a sentence within the range of federal guidelines. The representation was first reported by CNN.