Family nearly annihilated in 'domestic violence incident,' with 15-year-old gunning down family members

FALL CITY, WA - Police arrived at a lakeside Fall City home to find a nightmarish scene: A 15-year-old boy had allegedly murdered five of his family's seven members, including his father, Mark Humiston, 42, Humiston's wife, Sarah, and three of the suspect's four siblings. The suspect's sister, despite being shot three times, managed to survive and escape to a nearby neighbor, raising the alarm.

Homicide detectives with the King County Sheriff's Department are now investigating the near annihilation of the family as a domestic violence incident according to KOMO News. KCSO Public Information Officer Mike Mellis told reporters early on Tuesday “This is a significant event for the neighborhood," Mellis said. "And I’d call it a significant event for the region.”

Despite initial reports of a possible suicide by hanging, Mellis said that when detectives arrived at the Lake Alice home, the shooting had already stopped, with the teenaged sister receiving medical care from a trained neighbor before being transported to an area hospital.

"When deputies got here they discovered sort of a chaotic scene, but what they did when they entered the property is they immediately took one young male, teenage male into custody," Mellis told reporters. "What they found was a mix of injured and deceased persons."

“It was a traumatic scene," Mellis added per KOMO. "That discovery prompted the investigation.”

The Washington State Police has been called in to assist the Sheriff's Department with a Crime Scene Response Unit taking over forensics at the murder scene. However, KCSO will continue to lead the investigation. “It’s going to be a very significant, long investigation at this house," Mellis said.

The public information officer indicated that the area was known to be quiet and the home wasn't known to be a "problem house." 

“It’s a pretty nice area, low crime rate in general," Mellis continued, noting, "This is truly one of those neighborhoods you come to escape the hustle bustle problems of a larger city, it’s supposed to be a quiet place to be, but as you can see, the worst things can happen in any location."

"Everybody in this community is going to have some effect to this tragedy," he concluded.

Statement from public defenders who are representing the 15-year-old boy: pic.twitter.com/BMJv59cGMM

— Jeremy Harris (@JeremyHarrisTV) October 22, 2024

According to KOMO, Judge Joe Campagna of Clark Child and Family Justice Center in Seattle found probable cause on five counts of first-degree murder and one count of first-degree attempted murder. The judge ordered the 15-year-old to be held in secure detention with no contact between him and "surviving family members of the immediate family." The suspect reportedly waived his right to appear the King County Prosecuting Attorney Office said and he was instead represented by his defense attorneys.

King County Prosecuting Attorney's Office Director of Communications Casey McNerthney told reporters via email, "The King County Prosecuting Attorney’s Office will review the case for a charging decision when it is referred to us from Sheriff’s Office investigators. Prosecutors anticipate a case referral from King County Sheriff’s Office investigators as early as Thursday for a formal charging decision."