Clark County Coroner Mike Murphy told The Associated Press on Thursday that it will take several weeks for blood-toxicology test results to be complete, and authorities were still investigating the shooting.
The coroner said Thursday that an official cause of death was pending for 39-year-old Charles Joseph Vacca Jr. of Lake Havasu City, Arizona.
The Mohave County Sheriff's Office said no charges will be filed. They say the range was operating legally and that this was an accident.
The mother of the 9-year-old girl took cell phone video of the fatal shooting of Charles Vacca. The 9-year-old girl accidentally shot him with an Uzi sub-machine gun.
"This hand right there, turn this leg forward, there you go, just like that," said Charles Vacca in a video.
The operator of Bullets & Burgers where 39-year-old Vacca worked as an instructor in Dolan Springs, Arizona, said Vacca was an army veteran and was well trained.
"Really don't know what happened. I mean our guys are trained to basically hover over people when they're shooting, and if they are shooting right handed we have our right hand ready to push the weapon out of the way," said Sam Scarmardo.
Scarmado said the range followed industry standards that allow 8-year-olds and above to shoot. The Mohave County Sheriff's Office has already closed their investigation.
Classes in the valley at popular range Shooters World allow children 9-years-old and above to shoot at the range. A class for 4 to 9-year-olds teaches kids not to touch a gun and report it to an adult.
Carolann Burgeson is the general manager of Caswell's Shooting Range in Mesa.
"When the questions are, what was a 9-year-old doing shooting something like this? Well, it's not so much the age as the experience level," said Buregson.
She said it's not unheard of for young kids to shoot an automatic weapon, and as you can see in a YouTube video from Bullets & Burgers in the video above, it's allowed as long as they have parental permission and proper training.
"It's about providing a safe environment, and making sure the instructor and the person shooting is comfortable at that level," she said.
The Associated Press contributed to this story.