In this still image captured from video footage and supplied by the Mohave County Sheriff's Office, the nine-year-old girl is seen with shooting instructor Charles Vacca (left) before the incident. Picture: Mohave County Sheriff's Office, via EPA

Washington -

The manager of a firing range in Arizona where a nine-year-old girl fatally shot her instructor with an Uzi said on Wednesday that the business stresses safety with each client.

“Our guys are trained to basically hover over people when they're shooting,” Sam Scarmardo told Las Vegas television station KLAS.

The mishap that left 39-year-old Charles Vacca dead still puzzles him.

“We really don't know what happened,” he told the television station, noting that the range had never had any type of previous incident in more than 12 years of operation.

“I have regret we let this child shoot, and I have regret that Charlie was killed in the incident,” Scarmardo told KLAS.

The gun range and restaurant, Bullets and Burgers, offers tourist excursions from nearby Las Vegas. Patrons can shoot targets with a wide variety of firearms.

Scarmardo said the girl's parents signed waivers saying they understood the rules of the range and were standing nearby when the shooting occurred.

No laws were broken, according to police investigators quoted in news reports.

On its website, Bullets and Burgers said children ages 8 to 17 could shoot a weapon if accompanied by a parent or guardian.

The range's Facebook page describes Bullets and Burgers as a private outdoor shooting range set in the desert.

“We separate ourselves from all other Las Vegas ranges with our unique 'Desert Storm' atmosphere and military-style bunkers,” it says.

In a video recorded by the girl's father, Vacca can be heard telling her how to handle the gun. She does as he instructs and pulls the trigger on the automatic weapon. Vacca was shot when the Uzi's recoil sent the gun over her head, said the sheriff's department in Mohave County, Arizona.

The sheriff's department in Mohave County posted a version of the video that ends just before Vacca was struck.

The video posted by the sheriff's department shows the back of the girl, who is dressed in pink shorts, approaching the shooting range. Vacca places the Uzi in her hands and lets her take a single shot at a target in the distance.

Then Vacca, a former US soldier, tells the girl to keep a part of the Uzi held in “otherwise the gun won't fire” and instructs her to put a leg forward. Leaning in from her left, he apparently didn't expect her not to be able to hold the gun firmly as it recoiled.

After she fires the single shot, he says his last words: “Alright, full auto.” - Sapa-dpa