WASHINGTON — A Federal District Court judge may go forward with his plans to scrutinize the Justice Department’s request to drop the prosecution of President Trump’s former national security adviser Michael T. Flynn, an appeals court ruled on Monday.
The ruling had been expected since the full court voted to erase an earlier split decision by a three-judge panel that had ordered the trial judge overseeing the case, Emmet G. Sullivan, to dismiss the case against Mr. Flynn without review. Questions at oral arguments earlier this month suggested that a majority of the court was inclined to let Judge Sullivan proceed.
The main decision was unsigned, but it appeared likely that the judges on the full Court of Appeals for the District of Columbia Circuit voted eight to two. Only the two judges on the original panel who had ordered the case shut down immediately — Neomi Rao and Karen L. Henderson, both of whom are Republican appointees — signed dissents. Judge Thomas Griffith, a Republican appointee who is retiring after Monday, filed a concurring opinion.
The ruling means that Judge Sullivan can now proceed with his long-delayed plans to hold a hearing about the Justice Department’s request to dismiss the case before he rules on it.
The ruling was the latest step in a twisting legal and political journey for the case against Mr. Flynn, who had twice pleaded guilty to lying to the F.B.I. about his conversations with a Russian ambassador in December 2016 when the Justice Department, in a surprise move in May, moved to drop the case.
The case has since been enveloped in a legal fight over whether Judge Sullivan had to dismiss it since the Justice Department no longer wants to pursue it, or whether the federal rules of criminal procedure empowered him to scrutinize whether Attorney General William P. Barr sought to drop it for illegitimate reasons and — if Judge Sullivan were to decide that was what happened — whether he could instead sentence Mr. Flynn anyway.
The court majority ruled that it had been premature for Mr. Flynn’s lawyer, Sidney Powell, to ask the appeals court to intervene before Judge Sullivan ruled on the motion to dismiss the case. The court noted that Judge Sullivan may rule in Mr. Flynn’s favor after holding a hearing, or — if he does not — that she can come back to the appeals at that point. The Justice Department had backed her petition.
The court also rejected Ms. Powell’s argument that Judge Sullivan had shown bias and the case should be assigned to a different judge because he had appointed a so-called amicus, or friend of the court, to critique the government’s arguments and then asked the full appeals court to overturn the panel’s order.
“Quite simply, the only separation-of-powers question we must answer at this juncture is whether the appointment of an amicus and the scheduling of briefing and argument is a clearly, indisputably impermissible intrusion upon executive authority, because that is all that the district judge has ordered at this point,” the unsigned opinion stated.
It continued: “We have no trouble answering that question in the negative, because precedent and experience have recognized the authority of courts to appoint an amicus to assist their decision-making in similar circumstances, including in criminal cases and even when” the government is trying to drop a case.
The Justice Department has expressed alarm at Judge Sullivan’s plans to further scrutinize its decision, saying it would be inappropriate for him to attempt to probe its internal communications about the matter. But a lawyer representing Judge Sullivan at the oral arguments this month suggested that he may simply ask about abstract legal issues at the hearing, rather than pushing for disclosures of additional facts.
The department’s rationale for trying to drop the case has shifted across several filings, but it centers on the idea that Mr. Flynn’s lies were not material to any legitimate investigation and that the F.B.I.’s aggression in questioning him might give a jury a reason to acquit him.
The critic appointed by Judge Sullivan, a retired federal judge named John Gleeson, has argued that the rationale the Justice Department put forward for dropping the case despite Mr. Flynn’s guilty plea made no sense and must be a cover for a corrupt decision to show favoritism to a presidential ally. He urged Judge Sullivan instead sentence Mr. Flynn.