Two Utah brothers, 4 and 10, found dead; oldest brother arrested

(CNN) -- A 15-year-old Utah boy was arrested in connection with the slayings of his two younger brothers, ages 4 and 10, who were apparently stabbed to death in their home, authorities said Thursday.

Prosecutors have yet to file charges or decide whether to charge the youth as an adult, said Sgt. Susan Poulsen with Davis County Sheriff's Office.

The boy's name wasn't being released because he is a juvenile, authorities said.

The children's mother returned home Wednesday evening and found her youngest son dead on the floor, police said. The father has been out of town on active duty with the military.

She reported the death to 911 and added that her two other sons were missing, the sheriff's office said.

During a search of the home in West Point, Utah, deputies found the body of the 10-year-old boy, who like his younger brother, had "traumatic injuries," the sheriff's office said.

Just before midnight Wednesday, investigators from several jurisdictions found the oldest son in the Layton area, and he was taken to the hospital for the evaluation of minor injuries, authorities said. He is being held in Farmington Bay Youth Detention Center.

"We believe the suspect acted alone, and no other suspects are at large," the sheriff's office said in a statement.

Both boys' "manner of death appears to be consistent with penetrating knife wounds," the sheriff's office said. The medical examiner's office has yet to determine the cause of death.