Teen accused of killing parents, 3 siblings tried to frame slain brother: docs

A Washington teenager accused of killing his parents and three of his siblings called 911 afterward and told authorities one of the victims carried out the grisly attack before killing himself, according to court documents.

Around 4:55 a.m. on Monday, 15-year-old Andrew Humiston called the King County Sheriff’s Office and claimed his 13-year-old brother “just shot my whole family and committed suicide, too,” according to a probable cause statement obtained by NBC News. When deputies arrived at their $2 million residence in the Lake Alice neighborhood of Fall City— one of the most expensive in the country — they found Mark Humiston, 42, fatally shot alongside his wife, Sarah, and three of their children, ages 7, 9 and 13.

Deputies also discovered a sixth victim, the suspect’s 11-year-old sister, on the scene suffering from a gunshot wound. She later told them Andrew lied during his emergency call in a bid to blame their brother for the carnage. She further maintained that Andrew was the one who gunned down their family, using their father’s Glock handgun, which is typically kept in a lockbox. She added that Andrew was the only one of them who had the combination for it, according to the documents.

The surviving sibling also recalled playing dead to escape her oldest brother and then running next door for help. From there, she was rushed to an area hospital in critical condition for treatment and has since been released.

Andrew was arrested the same day of the shooting and on Thursday was formally charged with five counts of murder and one count of attempted murder in connection with the rampage, according to the King County Prosecuting Attorney’s Office. Investigators said he “systematically murdered his mother, father, two brothers, and sister, and attempted to murder his other sister.” He then “staged the scene prior to the arrival of first responders” to make it appear that the 13-year-old victim committed the murders and died by suicide.

Authorities further noted Mark Humiston, an electrical engineer, was shot four times while his wife was shot twice.

During a court appearance earlier this week, Andrew waived his right to appear and was ordered to have no contact with his surviving sister. His attorneys, Amy Parker and Molly Campera, emphasized that the “law presumes our client is innocent of these charges,” NBC reported. They described him as “a 15-year-old boy who enjoys mountain biking and fishing and has no criminal history.”