Judges considered Thursday whether the Freedom of Information Act requires the CIA and other federal agencies to process requests for release of the full 6,963-page Senate Intelligence Committee report on CIA interrogation practices that critics call torture.

Two D.C. Circuit appeals court judges, Sri Srinivasan and Harry Edwards, heard oral arguments in the American Civil Liberties Union’s appeal of an unfavorable lower court ruling. A third seat was empty due to Judge Merrick Garland’s Wednesday nomination to the Supreme Court.

Srinivasan, considered one of the front-runners for the nomination that went to Garland, took the lead in questioning attorneys and nodded supportively to show he grasped both sides of a technical, case law-dependent dispute.

A 499-page executive summary of the Senate committee report was released with redactions in 2014, revealing jarring accounts of weeklong sleep deprivation, waterboarding and use of purported medical procedures like “rectal feeding.”

The ACLU says the full document is a landmark work of oversight that could help ensure the U.S. never again uses harsh tactics tolerated during the George W. Bush administration, but Obama administration attorneys say there’s no avenue for its acquisition through FOIA.

At issue is whether the report became a FOIA-eligible “agency record” after being sent to the CIA and other federal agencies. Congressional records are exempt from FOIA, but courts have found under certain circumstances they can lose protected status.

Though it's difficult to predict rulings from oral arguments, Edwards made clear his skepticism of the ACLU’s position, saying the Senate committee was "very clear" about claiming authority over the report in 2009, in a communication to the CIA when research was underway.

The civil liberties group argues, however, the Senate committee did not assert control over the document when it transferred a copy to the CIA in 2014, thereby making it an agency record.

“Right now, the record is silence,” ACLU attorney Hina Shamsi said. “Silence does not equal control.”

Shamsi, director of the ACLU’s National Security Project, cited D.C. Circuit case law she says backs her position that reports drafted at the behest of Congress can lose their FOIA exemption when Congress does not clearly state its possession over them.

But Justice Department attorney Thomas Pulham cited his own case law, notably a 2013 opinion written by Garland that White House visitor logs are not “agency records” subject to FOIA, even though they are stored by the FOIA-able Secret Service.

Just whether the Senate committee asserted control over the report depends on the relevance of the 2009 communication, signed by the then-chairman and vice chairman of the committee,which the ACLU says was intended to shield Senate investigators as they performed research at a CIA-monitored facility. The ACLU says the letter was overridden by a 2014 transmission letter that mentioned no claim of ownership.

The 2009 communication says: “Any documents generated on the network drive referenced in paragraph 5, as well as any other notes, documents, draft and final recommendations, reports or other materials generated by Committee staff or Members are the property of the Committee and will be kept at the Reading Room solely for secure safekeeping and ease of reference. These documents remain congressional records in their entirety and disposition and control over these records, even after the completion of the Committee’s review, lies exclusively with the Committee.”

“We have a clear assertion of congressional control in 2009,” Pulham said, arguing the 2014 transmittal of the report to the CIA can't be considered the official voice of the committee, as only the chairman, Sen. Dianne Feinstein, D-Calif., signed it.

“The only uses [Feinstein’s letter] authorized are internal,” he further argued, not including public release. Shamsi said, however, the Feinstein letter used broad language authorizing use as the agency saw fit.

Though not betraying a bias, Srinivasan said matter-of-factly “you could have a situation where the transmission trumps the generation.”

A third judge who was not present at the hearing, Judge David Tatel, will listen to an audio recording of the Thursday arguments and help decide the outcome, Srinivasan said.

If the ACLU wins, the report won't immediately be released. The case likely would be remanded to a lower court judge who would monitor agencies' processing of FOIA requests. If the full report is found subject to FOIA, it's very likely large swaths will be withheld on national security grounds anyhow.