When Judge Justin Walker began his first day at the U.S. Court of Appeals for the D.C. Circuit, he was met with a high-profile records battle tied to former Special Counsel Robert Mueller’s probe.

Walker, formerly a U.S. district judge for the Western District of Kentucky, joined the D.C. appeals court after a testy confirmation process in the Senate, where Democrats alleged he was unqualified for the seat and questioned why Republicans were pushing his confirmation during the COVID-19 pandemic. GOP senators, led by Majority Leader Mitch McConnell, who has mentored Walker, defended the judge’s credentials, pointing to a new “well qualified” rating from the American Bar Association in doing so.