Software engineer 'killed' along with wife and children 'by 15-year-old son' at $2m home

Police have taken a teenage boy into custody for allegedly killing his family members in a shooting at their home on October 21.

The teenage boy, whom authorities have not yet named, is thought to have shot his software engineer father, his mother and his four siblings at their $2 million home in Washington, according to sources.

Only one of his sisters was able to escape, while injured from the shooting, according to a report by the Mail Online.

The girl hurt was 11 years of age and is currently in a ‘satisfactory condition’ at Harborview Medical Center in Seattle on Tuesday, hospital spokesperson Susan Gregg said.

Police have not revealed the names or ages of the victims besides the mother and father. Police have said they found the shot bodies of 42-year-old Mark Humiston and his wife Sarah.

The incident happened at the mansion in Fall City by Lake Alice where America has some of the most expensive homes, about 30 miles east of Seattle.

According to LinkedIn, Mark Humiston, who was originally from Texas, worked as an Associate Principal at Hargis Engineers in Seattle for almost 20 years.

King County Sheriff’s Office spokesman, Mile Mellis, has spoken about the incident and described the shooting as a clear ‘domestic violence incident involving a young man and firearms.’

He had also stated that there was ‘no significant confrontation’ with the young man when he was taken into custody by police.

Police arrested the teen at the home without incident (KOMO News)

Mellis added: “It’s very early stages of this investigation, but it’s going to affect many people.

“I can say that it's going to be really a tragic event for the community, for anybody who has any connection out here.”

Speaking about the overall safety of Fall City and its frequency of crime, he said: “[It is a] pretty nice area, low crime rate in general.'

“This is a place where people come to raise their families.”

Neighbors have also spoken to local media about the shooting and emphasized their own shock at the situation.

One neighbor, who spoke to KOMO News said: “They were the sweetest children, so polite. [They were] homeschooled and it just unfathomable what just happened.”

Neighbors have said that the couple (pictured) and their five children lived in the home (Facebook)

Another neighbor stated that inside the $2 million home lived the couple and their five children. Police have also said they believe everyone involved in the shooting is related.

On Tuesday, the 15-year-old's defense attorney said in court that his client has no criminal history and asked that his name not yet be released before a charging decision is made, which the judge granted.