The bodies of two West Point, Utah children, ages 4 and 10, were found in their home Wednesday night. According to a Davis County Sheriff’s Office statement, the brothers died from what appear to be knife wounds. The suspect in the murders is the victims’ 15-year-old brother.

The children’s mother found the the body of the 4-year-old on Wednesday evening. She called 911, and a police sweep of the home found the body of the 10-year-old. An hours-long search for the missing 15-year-old was then conducted. The boy was eventually found around midnight and taken to a local hospital.

On Thursday morning, “as a result of the emerging details,” the 15-year-old was arrested and taken to a juvenile detention center. Police suspect that the boy acted alone, but have released no further details on the crime, which they are investigating as a homicide. The cause of the 4-year-old’s and 10-year-old’s death will be officially determined by medical examiners.