Because of his age and nearly two decades of legal precedent that requires courts to treat children differently from adults, the 15-year-old boy accused in a mass shooting near Fall City will have a far more complicated court case than if he were even a year older.

The boy said his 13-year-old brother had killed their family and “taken himself out,” and that he was currently hiding in the bathroom.

The 15-year-old boy arrested in connection with five family members' deaths was charged Thursday with the murder of his parents and three of his siblings.

A 15-year-old boy is accused of shooting and killing five of his family members, then staging the scene to appear as if his brother had shot the family, according to charging documents from the King County Prosecuting Attorney's Office.

The bodies of Mark and Sarah Humiston and three of their children — ages 6, 9 and 13 — were found riddled with bullets inside the family’s $2 million home in Fall City, a suburb of Seattle, around 5 a.m. on Monday. A sixth victim, an 11-year-old girl, was shot twice and survived the horrific massacre, according to the charging documents.

A 15-year-old was charged Thursday with the murders of his parents and three siblings and in the attempted murder of another sibling who survived Monday’s attack at the family’s Washington state home.

A teen accused of killing five of his family members and trying to kill a sixth was officially charged by King County prosecutors on Thursday.