FILE PHOTO: The entrance to the Sandy Hook Permanent Memorial prior to the 10th remembrance of the Sandy Hook school massacre in Newtown, Connecticut, U.S., December 8, 2022. REUTERS/Michelle McLoughlin/File Photo

By Nate Raymond

(Reuters) -A federal appeals court on Friday upheld a Connecticut ban on assault weapons the state adopted after a gunman in 2012 killed 20 school children and six educators at Sandy Hook Elementary School in Newtown.

A three-judge panel of the New York-based 2nd U.S. Circuit Court of Appeals ruled that the 2013 ban remained valid even after a landmark U.S. Supreme Court ruling in 2022 on the right to bear arms in the U.S. Constitution's Second Amendment.

That decision, New York State Rifle & Pistol Association v. Bruen, was issued by the Supreme Court's 6-3 conservative majority and held that modern gun restrictions must be "consistent with this nation's historical tradition of firearm regulation."

Lawyers for a group of Connecticut residents, joined by organizations including the National Association for Gun Rights and the Second Amendment Foundation, argued the state's laws could not meet the standard the Supreme Court set.

U.S. Circuit Judge John Walker, writing for the panel, said the Democratic-led state's assault weapons ban was comparable to historical regulations on "unusually dangerous weapons" and targeted a type of firearm that was technologically distinguishable from those common at the nation's founding.

"The Founders faced no problem comparable to a single gunman carrying out a mass murder in seconds," wrote Walker, an appointee of Republican President George H.W. Bush.

The ruling upheld a trial judge's 2023 decision and marked the latest in a string of losses for gun rights advocates challenging state restrictions on assault weapons and large-capacity magazines. Five other appeals courts have also upheld such laws.

"This opinion is a brazen act of defiance against the Supreme Court," Hannah Hill, vice president of the National Foundation for Gun Rights, said in a statement.

Connecticut Attorney General William Tong, who defended the state's law, criticized the efforts of gun rights advocates.

"I'm under no illusion that today's clear decision will stop the gun lobby's relentless campaign to flood our communities with ever more deadly weapons," he said in a statement on Friday.

The U.S. Supreme Court in June turned away a challenge to a similar law in Maryland even as conservative Justice Brett Kavanaugh, in a concurring opinion, predicted the high court "presumably will address the AR–15 issue soon, in the next Term or two."

(Reporting by Nate Raymond in Boston; Editing by Edmund Klamann)