The dispute that prompted a federal appeals court to open up an avenue to civil liability based on claims of overly aggressive treatment by the Transportation Security Administration is set to go to trial, after the U.S. Department of Justice chose not to file a writ of certiorari with the U.S. Supreme Court.

Late last year, U.S. Solicitor General Noel Francisco asked the high court for an extension to see whether the office would like to appeal a precedential, en banc ruling from the U.S. Court of Appeals for the Third Circuit in Pellegrino v. U.S. Transportation Security Administration. In that decision the court held that TSA screeners could be held liable in a civil action for their conduct.

With the extended Dec. 30 deadline now passed, the Third Circuit's precedent stands, and the lawsuit, which is over a security search gone awry at the Philadelphia International Airport, is set to proceed.

In August, a split en banc panel determined that transportation security officers are "investigatory, or law enforcement officers" under the Federal Tort Claims Act, which waives the government's immunity for certain torts committed by "investigative or law enforcement officers."

The ruling, written by Judge Thomas Ambro, focused on the plain meaning of the statute.

"Words matter. This core tenet of statutory interpretation channels our conclusion today: TSOs are 'investigative or law enforcement officers' as defined in the Tort Claims Act at 28 U.S.C. Section 2680(h)," Ambro said. "They are 'officers of the United States' by dint of their title, badge, and authority. They are 'empowered by law to execute searches' because, by statutory command and implementing regulation, they may physically examine passengers and the property they bring with them to airports."

That decision diverged from a three-judge panel ruling from 2018, which held that the screeners were not law enforcement officers and barred recovery for the claims.

According to court papers, the incident that touched off the Pellegrino litigation occurred in 2006, when Nadine Pellegrino and her husband were planning to catch a flight to Florida from the Philadelphia airport. When a TSA screener began searching her bags, Pellegrino asked for a private search.

TSA screener Nuyriah Abdul-Malik did the private search, which Pellegrino has alleged was "unnecessarily rough and invasive," and caused damage to some of her belongings, court papers said. The interaction deteriorated, court papers said, and when Pellegrino left the room, she allegedly struck Abdul-Malik with a bag.

The TSA screener pressed charges, and Pellegrino was charged with felony aggravated assault, possession of instruments of crime, reckless endangerment, simple assault and making terroristic threats, the court noted. At Pellegrino's trial, however, Abdul-Malik, no longer a TSA employee, did not appear, so Pellegrino was found not guilty.

After the trial, in 2008, Pellegrino submitted a claim for $951,000 in damages to the TSA, which was denied. Then in 2009, she brought a civil rights action in the U.S. District Court for the Eastern District of Pennsylvania. The district court ruled in the government's favor on all claims, except one property damage claim, which the parties settled.

In holding that the screeners should be subject to liability, Ambro declined to look beyond the statute.

"Congress has created a remedy; we are simply giving effect to the plain meaning of its words," Ambro said.

Pellegrino's case is now set to proceed against the TSA. On Jan. 3, counsel for Pellegrino sent  U.S. District Judge J. Curtis Joyner of the Eastern District of Pennsylvania a letter requesting a status conference on the next steps.

Paul Thompson of McDermott Will & Emery, who is representing Pellegrino, did not return a call seeking comment. A DOJ spokeswoman said the office had no comment on the pending litigation.