A tragic incident in Fall City, Washington, has left five family members dead and revealed disturbing allegations against a 15-year-old boy accused of murdering his parents and siblings. Early Monday morning, two adults and three children were found fatally shot in their home, and police have now arrested the family’s 15-year-old son, following contradictory accounts of what occurred that night.
According to the King County Medical Examiner’s Office, the victims were identified as 43-year-old Mark Humiston, his 42-year-old wife Sarah, and their children Benjamin (13), Joshua (9), and Katheryn (7). The family’s sole survivors, an 11-year-old girl and her 15-year-old brother, have provided vastly different narratives, with the girl claiming her older brother committed the murders.
The ordeal unfolded when the 15-year-old called 911 and told officers that his 13-year-old brother had “shot the whole family” before killing himself. According to his statement to the dispatcher, the younger brother allegedly carried out the murders as a response to getting in trouble for looking at inappropriate content online. However, shortly afterward, the surviving 11-year-old sister escaped from the house and provided a very different story.
In a statement to investigators, the girl revealed that her 15-year-old brother had shot her and the rest of the family with a Glock handgun owned by their father. She stated that after pretending to be dead, she waited for the sounds to subside and then crawled through a window to safety, eventually finding refuge at a nearby neighbor’s home. The girl sustained injuries during the attack but has since been discharged from the hospital.
According to the probable cause statement, the 15-year-old was the only sibling who knew the combination to the lockbox where the handgun was stored, casting doubt on his claim that his 13-year-old brother was the shooter.
A detective wrote that the teen appeared to have “staged the scene” to implicate his deceased brother in the killings and had arranged the crime scene before calling 911 to mislead authorities.
Upon their arrival, law enforcement took the 15-year-old into custody, suspecting he had attempted to cover up his involvement by framing his younger brother. King County Detective Aaron Thompson stated in court documents that the teenager had “systematically murdered his mother, father, two brothers, and sister, and attempted to murder his other sister.”
The teen now faces five counts of murder and one count of attempted murder, all filed as acts of domestic violence. Prosecutors added a firearms enhancement to the attempted murder charge, which could result in a harsher sentence if he is convicted. Currently held in a juvenile detention facility, the boy is not permitted to have contact with his surviving sister, as ordered by the judge.
Prosecutors are also seeking to transfer the case to adult court, which could allow for more severe sentencing options if he is found guilty. While 16- and 17-year-olds charged with serious crimes in Washington are typically tried as adults, this process is more complex for younger suspects, requiring a “discretionary decline hearing.” This hearing would determine whether the case should remain in juvenile court or be escalated to adult court, though a final decision may take several months.
During a recent court appearance, the defense attorneys for the 15-year-old, Molly Campera and Amy Parker, argued that their client had no previous criminal record and described him as “a 15-year-old boy who enjoys mountain biking and fishing.” They reminded the court of the presumption of innocence and stressed that all evidence must be examined before any judgment is made.
The tragic deaths of the Humiston family have left the Fall City community reeling, as neighbors and colleagues mourn the loss. Mark Humiston, the father, worked as an electrical engineer at Hargis Engineers, where he was remembered as a respected colleague and friend.
In a public statement, his employer expressed their grief, stating, “We are blindsided and saddened by the tragic events that have led to the loss of a respected colleague, mentor, and friend, as well as the loss of immediate family members. [Mark’s] leadership and vision were integral within our firm, and he will be greatly missed. Our thoughts are with his surviving family, friends, and colleagues during this difficult time.”
As the case moves forward, the details surrounding this family tragedy continue to emerge, painting a devastating picture of betrayal, survival, and unanswered questions. For the surviving 11-year-old, the trauma of witnessing her family’s deaths and narrowly escaping with her life has left an indelible mark. The family and community now await further developments, as investigators work to unravel the full scope of this heartbreaking event.
