13 year old boy arrested planning Tacoma, Washington school shooting according to Pierce County Sheriff’s Office [VIDEO]

Washington state authorities arrested a 13-year-old boy after discovering a massive collection of firearms and writings about'mass shooting scenarios' in his house.

The alleged would-be killer, who has not been identified, was obsessed with 'past mass shooters' and 'idolized' them as he devised a terrifying plan to carry out his own murder spree, police said. 

The Pierce County Sheriff's Office said they went to the boy's house in Tacoma, Washington, after being informed on Friday afternoon that he was'making threats to kill.'

Following a search of his residence on Saturday morning, officers seized a 'significant quantity' of weapons. 

The boy also owned ‘loaded magazines with school shooter writings on them’ and clothes and writings that reinforce a ‘typical mass shooting scenario’, authorities said. 

13 year old Washington boy planned school shooting. Pictured arms cache which included 23 assault rifle and guns.

 Deputy Carly Cappetto with the Pierce County Sheriff’s Office told ABC News that a total of 23 firearms were found in the home, many of which appeared to be homemade using 3D printed parts.

Footage of the weapons seized showed long lines of weapons laid out on tables, most of which appeared to be long guns and AR-style rifles.

The teenager appearing in court pled not guilty to multiple felonies, including charges of attempted threat to bomb or injure a school, unlawful possession of a firearm and unlawful possession of fireworks, WGXA reported.

The boy’s parents have not been charged. Nevertheless it remained unclear how the teen was able to amass the arms cache without the teen’s parents knowing or presumably known about their child’s affairs.

13 year old would be school shooter parents say their son was ‘just trying to be cool’

His parents, speaking to KOMO News outside the courtroom, insisted the situation is a misunderstanding. His mother suggested that social media posts were an attempt to ‘be cool’ among peers. At the same time, his father described the charges as blown out of proportion, asserting that their son had no intention to harm anyone. Or did he?

A review of the 13 year old’s social media found a slew of posts the boy made, showing a ‘fascination of recent school shootings/mass casualty attacks’, court records showed. 

 

The teen also posted pictures dating back to June of him posing with guns and made remarks referencing shootings including the 1999 Columbine High School mass shooting and the 2022 Uvalde, Texas, elementary school massacre, cops said.

In an alleged similarity to the shooting of a Catholic school church in Minneapolis last month, the boy had written references to mass shootings and killers on magazines for his AR-style weapons.

Other alleged social media postings included the teen dressed in the attire of past school shooters, including one post that stated, ‘my time is almost hear (sic). I hope I kill y’all!!’

A search of the teen’s room led to authorities finding a gas mask along with a backpack of ammunition, including several AR style magazines which had writings on them referencing mass shootings.

Tacoma boy hadn’t been enrolled in school system since 2021

Officials claimed the 13-year-old was not currently enrolled in any school system and had last attended the Franklin Pierce School system in 2021.

In a statement to ABC News, the school district said: 'We were informed by local law enforcement personnel that a young person in our community had been arrested for allegedly preparing a school shooting.

'We continue to cooperate with the Pierce County Sheriff's Office to ensure that this individual poses no threat to our schools or the community as a whole.

Not immediately clear is why the boy had come not to be attending in the school system, what prior interactions with his prior school the teen had (had he been expelled?) along with which school the teen planned to attack and how the teen planned to carry out the alleged mass school shooting.

The teen remains in custody at the Remann Hall Pierce County Juvenile Detention Center, with a detention review hearing scheduled for Sept. 22. Investigators continue to review evidence, including social media posts.

Authorities thwarted an alleged school shooting in Washington state, arresting a 13-year-old boy. @TrevorLAult reports as police say they found an arsenal of weapons in his home. https://t.co/753rEwyIzE pic.twitter.com/ccGpc5gfRz

— World News Tonight (@ABCWorldNews) September 9, 2025