KING COUNTY, Wash. — The King County Prosecuting Attorney’s Office is seeking to move the case against a 15-year-old boy who is charged with killing his family to adult court.

The teen appeared in juvenile court Friday afternoon and prosecutors formally requested the case to be moved to the adult court system, but ultimately a judge will decide if that happens.

“That process in all types of cases takes months – the judge will have multiple opportunities to hear from prosecutors and defense before making a final decision,” said Casey McNerthney, a spokesperson for the KCPAO.

A hearing to decide if the case will go to adult court is set for June 4, 2025.

On Thursday, the teen was charged with five counts of first-degree aggravated murder and one count of attempted murder.

Charging documents allege the teen shot all six of his family members in the early morning hours Monday inside their home on Lake Alice Road near Fall City.

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

RELATED:Parents found dead in Fall City home identified, vigil held by community members

An 11-year-old girl survived being shot and ran to a neighbor’s house for help after escaping out a window. According to a police report, the 11-year-old police told that her 15-year-old brother had killed the family.

The 15-year-old suspect went to another neighbor’s house and called 911 while claiming it was his 13-year-old brother, Benjamin, had killed the family, according to the charging documents.

Sheriff’s investigators allege the 15-year-old boy staged the crime scene and then tried to blame his brother for the shooting.

RELATED:15-year-old accused of killing family, staging scene to frame deceased younger brother

According to a sheriff’s report, the 15-year-old boy was the only child in the family who knew the combination to a lockbox for a Glock pistol that was kept in the family’s home.

Attorneys for King County Department of Public Defense are representing the 15-year-old.

In a statement, defense attorney Amy Parker noted the only evidence they have been provided by the sheriff’s office and prosecutors is a 3.5 page probable cause statement.

Given the media interest in this case and the seriousness of these charges, we want the court to know that multiple people in the community have reached out to us who know our client, and they have attested to his good character. He has been described by them as kind and caring. This is a boy who has many friends, has pro-social interests, and has been a positive contributor to his community. However, we are not addressing release at this time. “We want the court to know this information, since the only information the Court has right now is the certification for probable cause and the charging documents.”

Earlier this week, Judge Joe Campagna issued an order Prohibiting the media from releasing the 15-year-old’s name.

The decision on whether the case will be moved to adult court will have major implications for the potential sentence, prosecutors said.

“If convicted of the charges in adult court, the sentence set by state judge is 25 years to life with a presumption of release after 25 years,” said McNerthney. “The state’s Indeterminate Sentence Review Board makes the release determination. If it remains in juvenile court, the 15-year-old could only be held until age 25 – less than 10 years from now – with no further sanctions.”

The teenager will be staying in secure detention at the King County Children and Family Justice Center.