A horrific family tragedy unfolded earlier this week in Fall City, Washington, when five members of a family were found fatally shot in their home.
The accused, a 15-year-old boy, is alleged to have killed his parents and three siblings. Initially, the boy claimed that his younger brother was responsible for the killings before taking his own life. However, the only other survivor, his 11-year-old sister, provided a different account, implicating her 15-year-old brother as the killer.
The incident took place just before dawn on Monday, in a waterfront house around 25 miles from Seattle. Law enforcement discovered the bodies of Mark Humiston, 43; Sarah Humiston, 42; and their children, Benjamin, 13; Joshua, 9; and Katheryn, 7. A probable cause statement reveals that Mark Humiston was shot four times, and Sarah twice, in what authorities believe to be a planned and deliberate crime.
The 15-year-old boy called 911, claiming his 13-year-old brother was responsible for the massacre, driven by frustration over recent discipline for accessing inappropriate content online. According to his statement, the younger brother then turned the gun on himself. But after interviewing the boy’s 11-year-old sister, investigators received a different story.
The girl, who survived the shooting by playing dead and escaping through a window, told police her teenage brother was the one who killed their family members with a Glock handgun owned by their father.
According to the affidavit, the girl described how her brother shot her and left the room, then returned to continue the attack on their family. She recounted hearing someone shout, “stop” and “help,” while she managed to escape. After fleeing the house, she reached a neighbor who called 911, corroborating her account and providing details that aligned with her statements to investigators.
The girl disclosed that her brother had knowledge of the combination to a lockbox where their father kept the handgun, suggesting a level of premeditation. Law enforcement found evidence that the 15-year-old attempted to stage the crime scene to support his murder-suicide story involving the 13-year-old. Detectives say he had set up the scene to mislead them, but upon further inspection, they identified him as the main suspect.
In light of the new evidence, the boy was charged with five counts of murder and one count of attempted murder in juvenile court. Each charge carries a domestic violence designation, and an enhancement was added to the attempted murder count due to the use of a firearm.
Prosecutors have filed a motion for a discretionary decline hearing, which, if granted, would allow the case to be transferred to adult court. Typically, 16- and 17-year-olds can be automatically charged as adults for serious violent crimes in Washington, but a 15-year-old requires a court hearing to determine if adult charges are appropriate. This process may take several months.
Defense attorneys Molly Campera and Amy Parker argued during a preliminary hearing that their client is a 15-year-old with no criminal history, who enjoys outdoor activities like mountain biking and fishing. They emphasized his presumption of innocence and expressed trust in the judicial process to ensure evidence is properly evaluated before reaching a judgment.
The tragedy has deeply affected the local community. Mark Humiston, who worked as an electrical engineer at Hargis Engineers, was remembered by his company as a respected leader, mentor, and friend. Hargis Engineers issued a statement expressing profound sorrow over the loss of Mark and his family, noting that his leadership had been vital to the firm and extending condolences to his loved ones.
The judge ordered that the 15-year-old boy remain detained without contact with his surviving sister, who has since been released from the hospital and is expected to receive ongoing support.
As the case proceeds, the teen’s defense team is preparing to challenge the evidence presented. Meanwhile, the prosecutors seek to ensure that the charges reflect the severity of the crime.
This tragic case has raised serious questions about the state of youth violence and the potential influence of legal precedents on how juvenile cases of such magnitude are handled in Washington.
