A fifth-grade teacher from New Fairfield, Connecticut was stricken with grief after he shot and killed a home invader who turned out to be his adopted teenage son.

Jeffrey Giuliano's sister, who lives next door, called him over to her residence yesterday around 1 AM to check on a suspected intruder. When he arrived, Giuliano spotted a person on the front lawn wearing black clothes and a black ski mask brandishing a "shiny object."

Fearing for his safety, Giuliano shot the person, killing him instantly. It was later revealed that the prowler was Tyler Giuliano — Jeffrey's 15-year-old son.

"I can't imagine what he felt when he took the mask off," one resident told CBS 2. "On a lot of different levels this is a real tragedy," said the town's First Selectman, John Hodge.

No charges have been filed, and police are still investigating why Tyler was trying to break into his aunt's house in a ski mask.

[screengrab via FOX CT]