Police have released footage of the moments before a nine-year-old girl accidentally shot and killed her shooting instructor who was teaching her to use an automatic Uzi submachine gun.
Charles Vacca was shot in the head on Monday at an outdoor shooting range in Dolan Springs, in north Arizona.
The 39-year-old was airlifted to University Medical Centre in Las Vegas but died shortly afterwards.
Mr Vacca was standing next to the girl at the Last Stop outdoor shooting range in White Hills when she pulled the trigger and the recoil sent the weapon over her head, investigators said.
The footage, reportedly filmed by the girl's parents, shows Mr Vacca helping the girl hold the gun, adjust her stance and then fire a single shot.
His last words to her are: "Alright, full auto."
It is not known if the range has an age limit on shooting or if the girl, who has not been named, had been through a safety class.
Firearms safety expert Ronald Scott said most ranges have an age limit and strict safety rules when teaching children how to shoot.
Instructors usually have their hands on guns when children are firing high-powered weapons, he said.
"You can't give a nine-year-old an Uzi and expect her to control it," Mr Scott added.