An Arizona road rage killer will be resentenced after an appeals court ruled that an AI-generated video message from his dead victim was improperly aired in court.

Gabriel Paul Horcasitas was found guilty by a jury of shooting and killing Christopher Pelkey, 37, during a confrontation at a red light in 2021. He was sentenced to 10 years behind bars.

But his legal team appealed, arguing that the trial judge should not have allowed an AI video, created by Pelkey's family, to be shown in court ahead of last year's sentencing.

The Arizona Court of Appeals agreed, ruling that Horcasitas, 55, must be resentenced because the AI clip "crossed that line".

"Rather than document an event or recording a particular moment, the AI video presents a depiction of the victim and his thoughts created from the imaginings of the victim's sister," the court of appeals wrote on Wednesday.

Horcasitas' lawyer, Kristen Reller, who filed the appeal, declined to comment.

Jessica Gattuso, an attorney for victims in the case, did not respond to a request for comment.

Pelkey's sister, Stacey Wales, told the BBC last year the family had used voice recordings, videos and pictures to recreate him for the AI video.

"To Gabriel Horcasitas, the man who shot me, it is a shame we encountered each other that day in those circumstances," said the AI version of Pelkey in court in 2025. "In another life, we probably could have been friends."

"I believe in forgiveness, and a God who forgives. I always have and I still do," the AI version of Pelkey - wearing a grey baseball cap - continued.

At the time of the sentencing, the judge who oversaw the case, Todd Lang, seemed to appreciate the use of AI.

"I loved that AI, thank you for that. As angry as you are, as justifiably angry as the family is, I heard the forgiveness," Judge Lang said. "I feel that that was genuine."

Almost everyone is now accounted for after dozens of hikers were airlifted to safety, an official says.

"It was a beautiful day - and then people were screaming," one hiker tells the BBC, as 14 people are missing.

About 15 people are thought to be missing or unaccounted for after flash flooding swept through parts of the iconic landmark.

A forensic linguist tells the BBC it's possible to glean crucial information about a person from just a few sentences.

Investigators hope the notes' "distinct linguistic characteristics" may be recognised by a member of the public.