A man who barricaded himself in a bedroom with a 17-year-old girl shot and killed her before turning his gun on himself Tuesday morning, investigators said.

Greene County officials told The Greeneville Sun in a story published online that at about 10 p.m. Monday night 29-year-old Jason Lynn McCamey, 29, of Morristown fired a shotgun blast through a sliding glass door and broke into the house where high school senior Katie Nicole Key, 17, lived with her family.

The intruder took the girl hostage and barricaded himself and the girl into a second-floor bedroom. It was not immediately clear if the girl was alone in the house at the time.

Officers attempted to negotiate with the man all night, but shortly before 2 a.m. they heard shots coming from the house, Sheriff Steve Burns said.

Officers then broke into the bedroom and found that both people had been shot. The bedroom doors had been tied shut with a rope from the inside.

Burns would not explain the relationship between the man and the girl other than to say they were acquaintances. He called the incident a murder-suicide.

A Tennessee Bureau of Investigation agent was called to assist with the investigation, Burns said.

Larry Bible, principal of West Greene High School, where Key was asenior and McCamey was a graduate, said everyone there was in shock.

Students had learned of the shooting early Tuesday morning he said.

Bible said Key had worked in the school office and was an A student.

"Everyone liked her," he said.

Greene County Medical Investigator Ray Crum said autopsies would be performed later this week.