(Newser) – A Connecticut man shot dead a masked man he believed was trying to break into his sister's home, only to learn that it was his own 15-year-old son. Police say elementary school teacher Jeffrey Giuliano received a late-night call from his sister, who lived next door, about a possible intruder outside her home. He armed himself with a handgun and fired after confronting an individual who was dressed in black, wearing a ski mask, and carrying a weapon in his hand, CBS reports. Police arrived at the scene to find the father overwhelmed with grief. Tyler Giuliano was pronounced dead at the scene. "I can’t imagine what he felt when he took the mask off," a neighbor says. Police are investigating but no charges have been filed. (Read more shooting stories.)