A 13-year-old boy was arrested in Tacoma, Washington, after investigators searching his home found a large cache of weapons, ammunition, potential explosives and writings that authorities say detailed mass‑shooting scenarios, the Pierce County Sheriff's Office said.
Deputy Carly Cappetto told ABC News that deputies seized 23 firearms from the residence, many of which appeared to be long guns or AR‑style rifles and some that included homemade components produced with 3D‑printed parts. Investigators also recovered loaded magazines bearing writings referring to school shooters, clothing and a series of social media posts that authorities said showed a fascination with previous mass casualty attacks.
Court records and law enforcement statements indicate the teenager had posted images dating back to June of him posing with guns and made remarks referencing the 1999 Columbine High School shooting and the 2022 Uvalde, Texas, elementary school massacre. Authorities also said they found an array of potential explosives and illegal fireworks at the property.
The juvenile faces charges that include attempted threat to bomb or injure a school, unlawful possession of a firearm and unlawful possession of fireworks. Sheriff’s Office officials said the boy was taken into custody after police were notified Friday that he was making threats to kill; officers conducted a sweep of the home the following morning.
Officials said the boy was not currently enrolled in any school district and had last been enrolled in the Franklin Pierce School District in 2021. In a statement to ABC News, the district said it was notified by local law enforcement and is working with the Pierce County Sheriff's Office to ensure the individual is not a threat to schools or the wider community.
Pierce County deputies said the boy’s parents have not been charged. Authorities noted that in the wake of mass shootings, investigations have at times led to charges or civil actions involving adults associated with suspects, but the sheriff’s office did not indicate any charges were pending against family members in this case.
In describing the evidence taken from the home, deputies highlighted the presence of writing on weapon magazines and other materials that echo language and imagery associated with earlier mass shootings. Authorities pointed to an apparent idolization of prior attackers as part of the alleged planning and said social media activity prompted part of their investigation.
The discovery adds to ongoing national discussions about the accessibility of weapons to minors, the rise of improvised or 3D‑printed firearm components and school safety. Law enforcement officials and lawmakers have repeatedly cited incidents involving homemade firearm parts and ghost gun components as complicating factors for regulation and enforcement.
Prosecutors handling juvenile cases generally weigh public safety concerns against statutes governing juvenile adjudication and confidentiality; the Pierce County Sheriff's Office did not provide details on how the case will be prosecuted. Further details, including the nature of the explosives and the specific provenance of the weapons, were not disclosed by investigators as of the latest updates.
Local and federal authorities often coordinate in cases involving large numbers of weapons, improvised parts and explosive materials, but the sheriff’s office said the investigation remains ongoing. Officials urged anyone with information to contact law enforcement as they continue to review the teenager's digital posts and the full extent of materials recovered from the residence.
The seizure and arrest follow several high‑profile attacks in recent years that have kept gun safety and school security at the forefront of public policy debates. Authorities said their immediate priority was ensuring there was no imminent threat to nearby schools or residents and that the juvenile’s detention has removed the alleged threat from the community while the investigation proceeds.