A 17-year-old senior at Payson High School is in intensive care at Scottsdale Healthcare Osborn where she is being treated for a gunshot wound.
LifeStar Ambulance officials said they responded to a report of a shooting at 9:40 p.m. Thursday and transported a female victim, who was later airlifted to the Scottsdale hospital.
Officials there would not comment on the girl's condition.
Payson High School administrators said they were aware of the shooting, but did not know any details.
Payson Police Sgt. Tom Tieman said the shooting is being investigated as accidental. Tieman said it is believed that Fred Ortiz, 18, fired the shot.
"We are still trying to piece it together," Tieman said. "We don't yet know if there was negligence involved."
Tieman also said investigating officers believe the shooting was possibly with a new firearm with which Ortiz was not familiar.
"We don't know if he knew how to handle it," Tieman said.
The incident occurred on Palmer Drive in the Country Club Vista subdivision.
Det. Steve Johnson is continuing the investigation into the shooting. Additional details will be published as they become available.