An appeals court ruling could mean the end of a federal lawsuit filed by the parents of a Black teenager who was naked and unarmed when he was shot and killed by suburban Oklahoma City police in 2019.

Police said 17-year-old Isaiah Lewis was naked when he broke into an Edmond home in April 2019 and attacked two officers. He was fatally shot after a stun gun didn’t stop him, Edmond police said.

Attorneys for Lewis’ parents said the teenager was experiencing a mental breakdown when the officers “unjustifiably” shot him.

But a three-judge panel of the 10th U.S. Circuit Court of Appeals in Denver on Friday ruled in favor of Officer Denton Scherman, who fired the fatal shots, saying he was entitled to qualified immunity for his actions, the Oklahoman reported on Saturday.

Attorneys for Lewis’ parents could ask the full appeals court to reconsider the ruling.

An autopsy found Lewis sustained gunshot wounds to his face, thighs and groin. Toxicology tests showed he had detectable amounts of a common antihistamine called diphenhydramine and THC, the active ingredient of marijuana, in his system.