NEW FAIRFIELD, Conn. (AP) — A popular fifth-grade teacher fatally shot a masked, knife-wielding prowler outside his house during what appeared to be a late-night burglary attempt, only to discover he had killed his 15-year-old son, police say.

"It's something out of a Hollywood script," said John Hodge, the first selectman, or top elected official, in the town of about 14,000 people. He said he couldn't recall another killing in his eight years on the job.

No immediate charges were brought against the father, Jeffrey Giuliano, in the shooting of his son, Tyler, around 1 a.m. Thursday. Police said they were investigating whether the father's handgun was registered.

State police said Jeffrey Giuliano got a call from his sister next door saying that someone might be trying to break into her home. Giuliano grabbed a gun and went outside to investigate, troopers said.

He confronted someone in a black ski mask and black clothing and opened fire when the person came at him with a knife, police said.

When officers arrived, the teen was lying in the driveway of his aunt's home with gunshot wounds and the father was sitting on the grass. The teen was pronounced dead at the scene. A state trooper pulled back the ski mask to reveal that the victim was Tyler Giuliano. It was unclear if his father had already realized it by then.

Police said the youngster's intentions were unclear and they were investigating whether he was actually trying to burglarize the house or if it was some type of prank gone wrong.

"All in all it's a tragedy," said State Police spokesman Lt. J. Paul Vance said.

Jeffrey Giuliano did not return a message seeking comment.

Alicia Roy, superintendent of schools in New Fairfield, said the elder Giuliano grew up in the town, holds summer music and zoology camps for his students and plays in a rock band that raises a lot of money for charity.

"''He wanted to teach in the community he grew up," she said. "He connects with the students. He's a caring person. Very interactive class."

Tyler Giuliano was a student at New Fairfield High School. He was described as an easygoing teenager who enjoyed spending time with his family and flying gliders and small planes out of the Danbury airport. He was a member of the Civil Air Patrol.