Boy, 15, charged with murder of 3 siblings, parents in Fall City; arraignment delayed

The arraignment for a 15-year-old boy, charged with murdering his three younger siblings and his parents at their home in Fall City early Monday, has been delayed.

The defendant appeared in the courtroom beside his attorneys on Friday. The arraignment was supposed to be an opportunity for him and his attorney to enter a plea to the charges. However, when King County prosecutors filed charges on Thursday, they also requested a discretionary decline hearing, which means they want the case moved to adult court. That request created a jurisdictional problem. Until the judge makes the decision, the case can’t move forward.

“State is asking that the court maintain the condition that Mr. Humiston be held in secure detention and that he be ordered to have no contact, direct or indirect with the surviving victim,” King County Senior Deputy Prosecutor Jason Brookhyser said.

Judge Kristin Richardson agreed and left conditions in place. The decline hearing has been scheduled for June 4, 2025. Until then, the prosecution and the defense will bring information and evidence to the judge in an effort to convince them about the jurisdiction. In the meantime, the defendant will remain in secure detention.

Earlier in the hearing, a defense attorney asked Richardson to order the media not to publish the 15-year-old’s name and picture. The King County Prosecuting Attorney’s Office (KCPAO) stated two media representatives spoke in opposition of the attorney’s requests.

However, the judge ordered the 15-year-old not be photographed, videotaped or recorded above the shoulders and noted that his face should not be on TV at this point, which included images from elsewhere. The judge also ordered the 15-year-old not be named.

Children, adults killed in Fall City identified

The three children killed in Fall City were identified as Benjamin Humiston, 13, Joshua Humiston, 9, and Katheryn Humiston, 7. In addition, the children’s parents who were also killed were identified as 43-year-old Mark Humiston and 42-year-old Sarah Humiston.

The 15-year-old was charged with five counts of aggravated murder in the first degree and one count of attempted murder in the first degree, according to the KCPAO. The attempted murder charge has a firearm enhancement and each of the six charges has a domestic violence designation.

He is currently in secure detention at the Patricia H. Clarke Children and Family Justice Center in Seattle. However, prosecutors may ask for the case to be moved to adult court.

A fourth child shot at the home — an 11-year-old  — was released from the hospital Tuesday and is expected to live.

Charging docs: 11-year-old tells dispatch her brother killed her family

According to charging documents, the 15-year-old called 911, saying “he just shot my whole family and committed suicide too.” During the conversation, the 15-year-old said his brother had killed their family and “taken himself out.” He said that he and another sibling were hiding in the bathroom in the house.

The 15-year-old then told officers a motive for his brother killing his family was that he had been “caught looking at pornography” and was “about to get in a lot of trouble,” as stated in the documents.

During the call with the 15-year-old, the communications center said it received another 911 call from a neighbor who said the 11-year-old sibling arrived at his door and said her family had been shot and they were all dead. He then called 911 and relayed that the 11-year-old was injured from a possible gunshot wound.

The dispatcher asked the 11-year-old if she knew who shot her family. She said she heard gunshots and screaming and then saw the 15-year-old’s face and that the 15-year-old was the one who shot her, according to documents.

Deputies then arrived and detained the 15-year-old in the driveway.

The 11-year-old, as stated by documents, later told law enforcement the 15-year-old was the only one who knew the combination to her father’s Glock lockbox. Also, the 15-year-old had recently gotten into “a lot of trouble” for failing some tests at school.

The Humiston parents home-schooled their children and Mark Humiston was an electrical engineer at Hargis Engineers in Seattle.

Hargis released a statement saying in part: “We are blindsided and saddened by the tragic events that have led to the loss of a respected colleague, mentor and friend. Mark’s leadership and vision were integral within our firm, and he will be greatly missed.”

Accused teenager makes first court appearance in Fall City shooting

The 15-year-old first appeared in court on Tuesday at the Clarke Center. Court-appointed attorneys told the court the teen exercised his option not to be present.

More details: Teen suspected of killing 5 in Fall City has first court appearance in case

At the time, Judge Joe Campagna found probable cause for five counts of murder in the first degree and one count of attempted murder. Campagna ruled the teen would remain in custody.

“I find the allegations, which have not been filed yet, nor proven are of the greatest possible seriousness,” Campagna said. “They create the highest possible risk to community safety, and I order secure detention.”

KIRO Newsradio spoke with neighbors who were fond of the family.

“I just keep seeing their faces, those children,” a neighbor named Lynn said. “I don’t know the details or anything. But I know something terrible happened there.”

‘A difficult scene:’ 5 killed, including 3 juveniles, in mass shooting at Fall City home

Law enforcement is continuing to investigate.

“Very, very sad,” King County Sheriff Patti Cole-Tindall told KIRO Newsradio in a press conference near the crime scene. “Very disturbed. I know that my team will do an excellent job in investigating this and we will determine the facts related to this incident.”

Now that the teen has been charged, he is scheduled to be arraigned Friday afternoon.

Contributing: Steve Coogan, MyNorthwest

Julia Dallas is a content editor at MyNorthwest. You can read her stories here. Follow Julia on X here and email her here.

James Lynch is a reporter at KIRO Newsradio. You can read more of James’ stories here. Follow James on X, or email him here.