NEW FAIRFIELD, Conn. (NBC) -- Connecticut State police are investigating a tragic shooting in New Fairfield.

Investigators say Jeffery Giuliano mistook his son for a burglar before shooting and killing the 15-year-old.

It began when Giuliano's sister and next door neighbor called her brother to say someone was outside of her home and attempting to get inside.

Jeffrey Giuliano went to investigate and found a masked person dressed in black.

When the person came toward him he fired, only realizing it was his son Tyler moments later after his ski mask was removed.

NBC