Boy, 15, claims brother killed 'whole family' before killing himself. But sister, 11, survives — and tells different story.

Five members of a family were found fatally shot in their Seattle-area home earlier this week. A 15-year-old boy is accused of murdering his parents and three siblings, but he claimed his brother carried out the murders before committing suicide.

However, the boy's 11-year-old sister who survived the massacre refuted her brother's murder-suicide story and declared that her 15-year-old brother is the killer.

The sister said she survived because she played dead and exited the house through a window.

Shortly before 5 a.m. Monday, two adults and three children were found dead inside their waterfront home in Fall City — approximately 25 miles east of Seattle.

WAPT reported that the King County Medical Examiner's Office identified the victims as Mark Humiston, 43; Sarah Humiston, 42; and their children Benjamin Humiston, 13; Joshua Humiston, 9; and Katheryn Humiston, 7.

The family’s father was shot four times and the mother was shot twice, the probable cause statement says.

The family's only survivors are an 11-year-old girl and a 15-year-old boy.

The 15-year-old boy notified the King County Sheriff's Office of the murders. He told police his 13-year-old brother "just shot my whole family and committed suicide, too," a sheriff's detective wrote in a probable cause statement, according to NBC News.

According to an affidavit of probable cause, the 15-year-old told a 911 operator that his brother did the shooting because he had gotten in trouble for looking at pornography.

However, the 11-year-old sister survived the mass shooting and contradicted her brother's account of the murders.

The girl told investigators that her 15-year-old brother shot her and her family with a Glock handgun that belonged to their father, according to the probable cause statement.

The girl informed investigators that the 15-year-old shot her and left the room; she then heard someone shouting "stop" and "help" before she escaped, the detective wrote.

The sister said she survived because she played dead and exited the house through a window. She then ran to a neighbor's home.

The girl was hospitalized and has since been discharged, a spokesperson for Harborview Medical Center in Seattle stated.

The girl told police the handgun was kept in a lockbox, and her 15-year-old brother was the only sibling who knew the combination, the probable cause statement says.

A few minutes after the 15-year-old called police, the neighbor called 911 to report that the 11-year-old had just survived a shooting by her teen brother, according to the affidavit.

The judge ordered the teenager — who's being held in a detention facility for juveniles — to have no contact with his surviving sibling.

Detectives determined that the 15-year-old attempted to frame his deceased brother for the murder of his parents and siblings and arrested him when they arrived at the crime scene.

The 15-year-old "staged the scene prior to the arrival of first responders" to make it appear that the 13-year-old brother committed the murders and then died by suicide, a detective wrote.

King County Detective Aaron Thompson wrote in the probable cause statement that the suspect "systematically murdered his mother, father, two brothers, and sister, and attempted to murder his other sister."

On Thursday, the 15-year-old was charged with five counts of murder and one count of attempted murder in juvenile court. All six criminal counts were filed with a designation that they were acts of domestic violence, according to the prosecuting attorney's office. The attempted murder count has a firearms enhancement, which allows for a more severe sentence if the suspect is convicted.

However, prosecutors filed a motion seeking a “discretionary decline hearing,” in which they would make the case that juvenile court should decline jurisdiction and have the case transferred to adult court — a process that could take months, according to the Seattle Times.

The outlet noted that 16-year-olds and 17-year-olds accused of murder and other serious violent crimes automatically can be charged as adults. However, a discretionary decline hearing is required to charge suspects 15 years old and younger as adults.

The teen's defense attorneys — Molly Campera and Amy Parker — said during a Tuesday hearing that "our client is a 15-year-old boy who enjoys mountain biking and fishing and has no criminal history. ... The law says our client is presumed innocent of these charges, and we are grateful for a judicial process that requires proof and evidence before there is a judgment."

The judge ordered the teenager — who's being held in a detention facility for juveniles — to have no contact with his surviving sibling.

The father worked as an electrical engineer for Hargis Engineers.

“We are blindsided and saddened by the tragic events that have led to the loss of a respected colleague, mentor, and friend, as well as the loss of immediate family members,” the company said in a statement. The man’s “leadership and vision were integral within our firm, and he will be greatly missed. Our thoughts are with his surviving family, friends, and colleagues during this difficult time.”

Like Blaze News? Bypass the censors, sign up for our newsletters, and get stories like this direct to your inbox. Sign up here!