A fifth grade teacher in New Fairfield, Conn., fatally shot a masked robber on Sept. 28, only to discover it was his 15-year-old son.

The father, Jeffrey Giuliano, was terrified when he found that the masked robber he shot was actually his adopted son, Tyler Giuliano.

No charges were filed against the father, but the police investigated to see if the gun he used was registered. After investigating, the local authorities said that the gun was registered under his name, according to local reporters.

The state police reported to ABC News that Jeffrey Giuliano received a call from his sister next door saying that there was a burglar inside her house. Giuliano then grabbed his gun from his house and went outside to investigate, state troopers said.

“The father went over to investigate and was approached by a masked person dressed entirely in black and holding a shiny object,” local authorities said in a statement.

According to the statement released by the police, it appeared the masked intruder was armed with a weapon and about to attack the father, who then discharged his personal handgun at the intruder.

“(Tyler) was lying on the ground in the driveway with obvious gunshot injuries, holding a weapon,” the statement said.

A state trooper on the scene pulled back the mask and revealed that the masked gunman was in fact, Jeffrey Giuliano’s son, Tyler, who was pronounced dead at the scene. The police are currently investigating whether the young boy was pulling a prank or simply trying to burglarize the house.

“We truly don’t know. We’ll look at the family dynamics, his school locker, cell phone, computer to figure out what’s going on,” said Lieutenant J. Paul Vance, a spokesman for the Connecticut State Police, to ABC News.

Jeffrey Giuliano and the community around him are currently mourning the loss of Tyler. Members of the St. Paul’s student body also reacted to the news of this tragic death of someone near their age.

“I think that it is a terrible thing, and I couldn’t imagine this happening to someone in my family,” said senior Patrick Donadieu.

“I just learned of this news a few days ago and I think that it is a shame that this young kid’s life was taken as early as it was. It was most likely just an accident, and the father never meant to shoot his son,” said senior Ryan Malone.