Washington teen accused of killing family, surviving sister tells how she escaped

Prosecutors in Washington accused a 15-year-old boy child in murders his parents and three brothers in a house in an affluent neighborhood outside Seattle.

The suspect faces five counts of first-degree murder and one count of attempted murder in connection with Monday’s rampage in the unincorporated community of Fall City, according to the King County Prosecutor’s Office.

His parents, Mark and Sarah Humiston, as well as three of his siblings, ages 7, 9 and 13, were found dead at the scene when officers arrived.

An 11-year-old girl, one of the suspect’s two younger sisters, was injured in the shooting and has since been released from a Seattle-area hospital. She managed to escape by playing dead before running to a neighbor’s house for help, according to an arrest affidavit filed in Washington Superior Court for King County.

The alleged gunman was arrested at the scene and has since been held in a juvenile detention center. At a court hearing Tuesday, he waived his right to appear and a judge found probable cause to arrest him on five counts of murder and one count of attempted murder. Authorities and his attorneys said he has no criminal record.

Prosecutors said they will request that the case be moved from juvenile court to adult court. If convicted in juvenile court, the teen could be detained only until age 25, prosecutors said. If convicted in adult court, he could be sentenced to 25 years to life in prison with a legal presumption of release after 25 years.

Molly Campera and Amy Parker, the attorneys representing the suspect, did not immediately respond to a request for comment on the charges, which were filed Thursday. After the initial hearing in juvenile court, they issued a statement reiterating that their client has no criminal record. They described him as a teenager who likes mountain biking and fishing.

“The law says our client is presumed innocent of these charges, and we welcome a judicial process that requires evidence and proof before there is a trial,” the statement said.

Teen shot parents, siblings, tried to frame brother, records show

The first call to report the shooting was from the suspect himself, according to an arrest affidavit. Just before 5 a.m., the teen called 911 and told the operator that his 13-year-old brother “just shot my whole family and killed himself,” he said.

Investigators said based on the evidence, the suspect shot his parents and siblings and then manipulated the scene so he could blame his brother.

“It appears that (the suspect) systematically murdered his mother, father, two brothers and sister, and attempted to murder his other sister,” an arrest affidavit said. “He then staged the scene before first responders arrived to make it appear that (his brother) had committed the murders and then committed suicide.”

In an interview with investigators, the 11-year-old girl said she woke up to the sound of a gunshot and saw one of her brothers and her father lying in the hallway, the affidavit says. She told police she saw the suspect shoot her sister.

The suspect then entered his room and shot him at least once, according to the affidavit. He closed his eyes and held his breath for a moment until the suspect left the room. He managed to escape from the house through his bedroom window and ran to a neighbor’s house, who called 911.

The 11-year-old girl said she recognized the gun “as her father’s silver Glock pistol,” the affidavit says. She told authorities that her father kept the gun in a small safe that was occasionally located near the front door so he could take it to work. He added that of the four children, the suspect was “the only one who knew the combination” to the safe.

A black Glock pistol was found at the scene, according to the affidavit.

When investigators asked her what problems the suspect was having at home, she told them that he had “recently gotten into ‘a lot of trouble’ for failing some tests at school.”

The father was an engineer, the mother was a registered nurse.

Mark Humiston was an electrical engineer at Seattle-based consulting firm Hargis Engineers, where he had a reputation as a mentor who brought leadership and vision to the company, company spokesman Chris Sheldon said in an email to USA TODAY.

“We are shocked and saddened by the tragic events that have resulted in the loss of a respected colleague, mentor and friend, as well as the loss of immediate family members,” a company statement said.

Sarah Humiston had a registered nurse license, according to the Washington State Department of Health website. Public records show his license expired in 2022.

Mourners gathered Tuesday night at Fall City United Methodist Church to mourn the Humistons and their children. Local residents who knew the couple and their children said they were an apparently happy family well known in the community.

“They were very strong Christians. They loved God. You could tell,” neighbor Camille Sharp. told KOMO News. “It’s one of those clichés that everyone says on the news: ‘You never suspect this,’ and it’s true.”

This story has been updated to include new information.

Contributing: Eric Lagatta and Jonathan Limehouse

This article originally appeared in USA TODAY: Washington shooting: teenager accused of killing his parents and three brothers