A 15-year old boy has allegedly killed his two younger brothers, aged 4 and 10, in West Point, Utah, reports Yahoo News.

Thursday night, their mother found her four-year old dead inside their home. Police say she couldn’t find her other two sons when she contacted authorities.

According to ABC 4, Davis County sheriff deputies later found the ten year old dead inside the home.

“It appears they did from a knife like wound,” says Sheriff Todd Richardson.

The 15-year old fled the home but Layton police found him shortly after midnight.

“He had some wounds,” Richardson says.

After being questioned, Richardson says he was booked into a juvenile facility in Davis County.

“He acted alone,” he says. “There are no others at large.

Neighbours say they are shocked.

“I’ve talked with their mother many times but I never got the sense that there was this kind of trouble,” says neighbor Lindsey Caballero. “You could tell there was a sibling rivalry between the biological son and the adopted boys. But I never imagined it could go this far.”

“This is really hard to understand,” said one student who said she sits next to him in a science class. “He is very friendly and always talking about school work and he’s very smart.”

The bodies of the four-year old and ten-year old were removed from the house early Thursday morning and taken to the medical examiner for an official autopsy report.

Their father, who is in the militar is reportedly returning to West Point.

A Bernalillo County sheriff’s detective questioned the teen Saturday night and the details of their conversation were spelled out in the statement.

Sadly, this isn’t the first case of a sibling being charged with murder this year; a New Mexico teenager who is accused of fatally shooting his parents and three younger siblings told authorities he was annoyed with his mother and had been having homicidal and suicidal thoughts, according to a probable cause statement.

Officials: 15-year-old killed parents, 3 younger siblings in New Mexico home

Older brother held in deaths of 2 younger siblings