WASHINGTON (AP) — A federal judge must end his “unlawful, unnecessary and futile" contempt investigation into whether the Trump administration ignored an order blocking the deportation of planeloads of Venezuelan migrants to El Salvador, a Justice Department attorney argued Tuesday before an appeals court that often appeared to be deeply skeptical of the government's case.

Judges from the full U.S. Court of Appeals for the District of Columbia Circuit heard three hours of arguments in the latest chapter of a case that has been a recurring flashpoint in President Donald Trump’s escalating conflict with the federal courts.

Justice Department attorney Brett Shumate argued District Court Chief Judge James Boasberg has no basis or authority to continue with his inquiry because a prosecutor — not a judge — is responsible for investigating crimes.

“What's gone off the rails in this case is that the district court has purported to investigate,” Shumate said.

In April, a divided panel of three D.C. Circuit judges ruled that Boasberg must end his “intrusive” contempt investigation of the Trump administration. But the questions posed at Tuesday's hearing suggest that the full court of 11 judges could give Boasberg a green light to proceed with his inquiry. The judges didn't indicate how soon they would rule.

Judge Patricia Millett questioned why Boasberg shouldn't be allowed to continue with his inquiry so he can determine if other government officials merit additional scrutiny for possible criminal contempt.

“Are district courts allowed to decide if people have engaged in contempt in front of them?” asked Millett, who was nominated to the court by Democratic President Barack Obama.

“The district court loses the authority to investigate,” Shumate said.

“That's not my question,” Millet interjected, raising her voice. “This is all about wordplay here on what you mean by the word ‘investigate.’”

On March 15, 2025, Boasberg issued a temporary restraining order barring the administration from transferring groups of Venezuelan migrants to El Salvador under an 18th century law. After the order was entered, two planeloads of migrants protected by the order departed from the U.S. on their way to El Salvador, where they were locked up in one of the world’s most violent prisons.

Boasberg gave a verbal order for the aircraft to turn around. The administration denied violating it or a subsequent written order, but Boasberg has said the Trump administration may have acted in bad faith by trying to rush Venezuelan migrants out of the country.

The administration has said then- Homeland Security Secretary Kristi Noem was responsible for the transfer decision. On Tuesday, however, D.C. Circuit judges suggested that Boasberg should be able to identify other possible targets for a contempt investigation before referring the matter to a prosecutor.

The case represents a major front in an escalating conflict between Trump and the federal judiciary, which has often blocked some of the president's most ambitious and legally dubious initiatives. In case after case, the administration has demonstrated an unprecedented willingness to skirt or even defy court orders.

Judge Cornelia Pillard, also an Obama nominee, said it undermines courts’ authority if the executive branch treats judicial orders as “optional” and is allowed to ignore them “with impunity.”

“The separation of powers respects the separate and co-equal authority of the different branches,” she said. “Really, at bottom what this case is about is whether (federal) courts are at the mercy of the executive.”

Pillard asked Shumate if he could help her “feel more comfortable” about the administration's perspective on that issue. Shumate said the department is “always advising our clients to comply with court orders.”

“It's also the right thing to do," he said. “We have to respect court orders, and the government in this case did comply with the order. I know there may be disagreement on that.”

The Justice Department says it didn't violate Boasberg's order “as it was best construed” and accuses the Obama-nominated judge of pursuing the contempt inquiry “with myopic and single-minded determination.”

American Civil Liberties Union attorneys say the government's decision to ignore Boasberg's order had “devastating consequences” for the migrants who were flown to El Salvador and held for months in a mega-prison known as the Terrorism Confinement Center, or CECOT.

“Plaintiffs’ four months at CECOT were nothing short of barbaric,” ACLU attorneys wrote. “They were subjected to horrific physical and psychological abuse, and deprived of food, water, and medical care. They were regularly severely beaten by guards and subjected to other physical abuse, including being shot at close range with rubber bullets.”

Judge Neomi Rao, a Trump nominee who wrote the panel's majority opinion in April, said she couldn't find a case in which a criminal contempt ruling was upheld under comparable circumstances.

“I don't think that should be a point in the government's favor,” ACLU attorney Lee Gelernt responded. “The reason is because no prior (Justice Department) or administration has ever taken these kind of egregious actions."

Trump has called for impeaching Boasberg, and the Justice Department filed a misconduct complaint accusing Boasberg of making improper public comments about Trump and his administration. In a rare rebuke, Supreme Court Chief Justice John Roberts publicly rejected calls for Boasberg’s impeachment.