A 15-year-old killed siblings, it is being alleged in Utah. A fifteen year old boy is being held in juvenile detention after being questioned for the deaths of his two younger brothers.

The 15-year-old son had fled the house after the bodies of his two brothers were uncovered, but he was found by police. An ex-neighbor who once found the boy throwing rocks over a fence onto his trampoline said the 15-year-old was "different."

The mother found her four-year-old son dead inside their home on Thursday night. When the woman couldn’t find her two other sons she called police to the scene. Davis County sheriff deputies also found the family’s ten year old dead inside the home.

Sherriff Todd Richardson said, “It appears they died from a knife like wound."

Richardson says Layton, Utah, police found the 15-year old shortly after midnight. Richardson said, "He had some wounds."

The boy was booked into the juvenile facility in Davis County after he was questioned.

Richardson added, "He acted alone. There are no others at large.”

The sheriff said that the father has been notified. A neighbor said the father works for the Air Force as an engineer. Authorities first said that the father was on active military duty, but they later changed their minds and said they were unclear about his status. The neighbor said the couple had spent time in South Korea before moving to Utah.

The 15-year old attends West Point Junior High. One student who says she sits next to him in science said "This is really hard to understand. He is very friendly and always talking about school work and he's very smart.”

Neighbors described the 15-year-old as a runner. His father ran marathons as well.

Angela Moffo, a mother in the neighborhood said "My son is devastated right now. My son played with the two boys. They were nice kids."

Lindsey Caballero, another neighbor, said she spoke with the boys’ mother often. She said that the 15-year old is the biological son and that the two brothers who were killed are adopted. Caballero said that three other siblings were not home at the time of the deaths.

Caballero said, "I've talked with their mother many times but I never got the sense that there was this kind of trouble. 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."

The bodies of the four-year old and the ten-year old were taken to the medical examiner early Thursday morning. Police say the 15-year old will be charged in the juvenile system.

by Tony Sokol