A 15-year-old boy from Fall City has been charged with five counts of aggravated murder and one count of attempted murder in the deaths of his parents and three siblings.
Thursday the King County Medical Examiner’s Office identified those victims as 43-year-old Mark Humiston, 42-year-old Sarah Humiston, 13-year-old Benjamin Humiston, 9-year-old Joshua Humiston, and 7-year-old Katheryn Humiston.
All five suffered gunshot wounds to the head.
According to court documents—the investigation began after the 15-year-old suspect called 9-1-1 trying to pin the murder on the brother he’s being accused of killing.
In the call, the boy was “out of breath” and said his 13-year-old brother had “just shot my whole family and committed suicide too.” The suspect went on to say he was currently hiding in the bathroom.
According to court documents, the boy told dispatchers his younger brother had been caught looking at pornography the night before, and that he was about to be in a lot of trouble.
However, while that call was happening, investigators say the 9-1-1 call center received a second call from a neighbor who said the suspect’s younger sister had just ran from the home to their front door.
She told them she woke up to the sound of gunshots and screaming, and then saw her brothers face before he allegedly shot her, causing injuries to her neck and hand.
Investigators say the girl described “holding her breath and playing dead” as her brother stood over her. She said she made a run for it after she heard him walk out of the room talking to someone on the phone.
Despite her condition, the girl was able to identify her 15-year-old brother as the individual responsible for the attack
Investigators say that when police arrived the 15-year-old was taken into custody before being taken to the Sammamish Police Station, where attorneys told police the suspect would not be talking to them.
According to court documents, the sister told police her brother had recently “gotten into a lot of trouble” after failing some tests at school.
She also allegedly told police her brother was the only one who knew the combination to her father’s glock lockbox which was sometimes stored near the front door so that he could take it to work.
Investigators say they believe the suspect “systematically murdered” his mother, father, two brothers, and sister and attempted to murder his other sister. Documents continue to say the suspect then “staged the scene prior to the arrival of first responders to make it appear that his younger brother had committed the murders and then killed himself.”
Authorities are treating the case as an instance of domestic violence, and the investigation is ongoing.