dramatic new details about the young girl just nine years old, seen here at a shooting range in Arizona, learning how to shoot an uzi when the unthinkable happens, she shoots and kills her instructor.... See More
dramatic new details about the young girl just nine years old, seen here at a shooting range in Arizona, learning how to shoot an uzi when the unthinkable happens, she shoots and kills her instructor. That video is sparking debate tonight about guns and how young is too young. ABC's Clayton Sandell now. Reporter: Tonight, the chaotic aftermath of a split-second accident. 911, what is your emergency? I have a gun range officer that got shot in the head. Reporter: The moment a 9-year-old girl having fun with her family at a popular shooting range outside Las Vegas -- Reporter: --Suddenly loses control of an automatic uzi submachine gun, shooting her instructor, 39-year-old Charles Vacca. Is he beating? Yes, he's having convulsions. Reporter: According to a newly released police report, after pulling the trigger, the girl dropped the gun, grabbing her shoulder as if she was injured, telling her mother the gun was too much for her. The girl's father tells investigators nobody immediately realized that Vacca was gravely wounded. The shooting is renewing debate over how young is too young for kids on the firing line. Individual ranges set their own age limits, sometimes as young as six. Vacca's coworkers tried desperately to save his life. Breathe, Charlie, breathe. I don't think he's going to make it. Reporter: Tonight the girl's family says they are devastated by Vacca's death and praying for his family. Clayton Sandell, ABC news, Denver.
This transcript has been automatically generated and may not be 100% accurate.