15-year-old accused of killing family, staged scene to frame deceased younger brother

KING COUNTY, Wash. – King County prosecutors said the 15-year-old boy accused of fatally shooting five family members initially blamed his younger brother for the killings. Prosecutors believed he even staged the crime scene and planted the murder weapon on his deceased brother's body.

Prosecutors charged the 15-year-old on Thursday with five counts of aggravated first-degree murder and attempted first-degree murder. According to court documents, the attempted murder charge includes a firearms enhancement, and each of the six counts includes a domestic violence designation.

KOMO News is not releasing the teenager's name because he has been on trial as a juvenile since Thursday. The case could be moved to adult court after a judge hears from both the defense and prosecution.

According to the King County Sheriff's Office, officers found five dead family members in their home on the 7700 block of Lake Alice Road Southeast, near the Lake Alice public boat launch, after multiple 911 callers reported a possible shooting.

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The King County Medical Examiner's Office (KCME) identified the shooting victims as 7-year-old Katheryn Humiston, 9-year-old Joshua Humiston, 13-year-old Benjamin Humiston, 43-year-old Mark Humiston and 42-year-old Sarah Humiston.

The KCME report indicated that all five family members died of gunshot wounds in their home.

According to court documents, an 11-year-old girl escaped the home after being shot and ran to a neighbor's house for help. The girl was taken to the hospital for her injuries and released Wednesday afternoon.

According to court documents, the 15-year-old called 911 and appeared “out of breath.” Documents show the teen said, “He just shot my whole family and also committed suicide.”

While speaking to the emergency dispatcher, he claimed that his brother killed their family and “got himself out” and that he was currently hiding in the downstairs bathroom of the house.

Court documents also revealed that the 15-year-old told police that a possible motive for his brother killing everyone was that he had been caught watching pornographic videos the night before and was going to get in big trouble.

During the 15-year-old's 911 call, prosecutors said the teen's 11-year-old sister ran to a neighbor's house injured with a gunshot wound to the neck. According to court documents, she told her neighbors that everyone in her family was dead and that her 15-year-old brother was the shooter.

Prosecutors said the girl told them she was awakened at about 4:50 a.m. by gunfire and screaming in her home. They said she then saw her brother's face and he shot her.

The girl said her brother then left the room and began checking her other sibling's pulse and breathing. Moments later, she told authorities that her brother had returned to her room. Fearing she would be shot again, she said she played dead and held her breath.

After the neighbor called 911, police arrived and took the 15-year-old boy into custody.

Court documents say the 15-year-old's next court appearance is scheduled for Oct. 25 at 1:30 p.m. at the Clark Child and Family Justice Center.