Prosecutors argue that if the case stays in juvenile court, the teen could be released to a group home within a year.
A King County judge is set to decide whether a 17-year-old accused of killing his parents and three siblings in their Fall City home will face murder charges as an adult, a decision that could affect how long he ultimately remains in custody.
Over the past two weeks, the court has heard testimony from family members concerned about the children's upbringing and home life, as well as from experts on the teen's mental health.
Prosecutors argue that if the case stays in juvenile court, the teen could be released to a group home within a year. They're pushing to have him tried as an adult, saying that's the only way to properly address both his needs and the safety of the community.
Prosecution: A 'controlled and methodical' attack
It's been nearly two years since investigators say the teen, who was 15 years old at the time, shot and killed his parents and three siblings inside their family home.
During closing arguments, prosecutors walked through the killings in detail, describing a deliberate sequence of events.
"He was controlled and methodical," said Jason Brookhyser of the King County Prosecuting Attorney's Office. "He fired two rounds when he first opened fire on his mom, Sarah, in her bedroom."
Prosecutors allege the teen staged the scene to look like a murder-suicide, then tried to frame his 13-year-old brother for the crime. But investigators say the younger brother's wounds were inconsistent with suicide, and the couple's 11-year-old daughter, who survived the attack, identified her oldest brother as the shooter. KOMO News is not naming the accused teen because he is a minor.
"That is a sophisticated act to stitch together a false story that would allow [the accused teen] to get away with killing his whole family, while leading all of us to believe [his younger brother] was responsible for it," Brookhyser said. "That is terrifying behavior."
"This was not a single, isolated act of violence," Brookhyser added. "This took time. There were a whole series of decisions, over and over and over again, when he could have stopped. Five lives — almost six lives."
Defense: Abuse, mental illness and a 'coercively controlling' home
Defense attorneys say the teen endured psychological and physical abuse and was raised in a household with extreme religious beliefs.
"In addition to multiple concussions and a childhood marked by emotional and physical abuse, he was suffering from bipolar I disorder, post-traumatic stress disorder, and was continuing to live in a coercively controlling environment," said defense attorney Kristen Gestaut.
Gestaut said the night before the killings, the teen was dealing with several compounding issues, including pneumonia.
"He was having intrusive, psychotic thoughts," she said. "Dr. Peterson believes that it was compounded by delirium and that he was sleep-deprived. This was not a willful offense."
What's next
Both sides disagree on whether an adult or juvenile facility would give the teen the best chance at receiving the treatment needed for possible rehabilitation.
The judge will review the evidence presented and issue a decision Oct. 14.
