A judge has ruled that a 17-year-old accused of killing five family members in their Fall City home will be tried in adult court rather than remain in the juvenile justice system.

King County Superior Court Judge Veronica Galván made the decision at a Wednesday hearing in King County Juvenile Court, after weeks of testimony and evidence. The teen faces five counts of first-degree murder and one count of attempted murder in the deaths of his parents and three younger siblings two years ago. He was about a month past his 15th birthday at the time of the alleged killings.

Galván cited the extraordinary nature of the allegations and the teen’s significant mental health needs. His defense lawyers argued that alleged abuse at home, his age and his mental health weighed against moving the case to adult court. Relatives also submitted letters supporting him.

If convicted in adult court, the teen faces a prison sentence ranging from a minimum of 25 years to life. A juvenile-court conviction would have meant release at age 23.