A 13-year-old Washington state boy has been arrested after authorities alleged he had “school shooter ideations” and a stockpile of weapons for an attack.

The Pierce County Sheriff’s Office arrested the teenager, whose name has not been released, on Saturday after it received information late Friday that a teen in the area “was making threats to kill” and had said he had access to guns, the sheriff’s office said a statement.

A search of the teenager’s home upon his arrest yielded “a large quantity of firearms that were both secured and unsecured,” the sheriff’s office said.

“Loaded magazines with school shooter writings on them, and clothing and writings that would support a typical mass shooting scenario, were confiscated,” it added.

Sheriff’s Deputy Carly Cappetto said in a video Monday that officials found 23 firearms and several boxes of ammunition at the teenager’s home. Many of the firearms lacked serial numbers, meaning they were illegal, Cappetto told NBC affiliate KING of Seattle.

There were firearms mounted on the walls that were “accessible at any time” and unsecured handguns throughout the residence, Cappetto said. Some of the firearms were secured in a safe, according to court documents.

Evidence collected from the suspect’s bedroom indicates he was “obsessed with past school shooters and imitated similar behaviors with photos and inscriptions throughout his room.”

Officials also found what they described as a “go bag” in the teen’s bedroom, carrying multiple boxes full of ammunition and AR-style magazines, according to go documents. Authorities allege that materials indicate the teenager was prepared and ready for an attack.

“It appeared the suspect had everything ready to go to commit a mass shooting type of incident,” Cappetto said.

The teenager’s target was unknown, Cappetto told KING, “but it is clear it was only a matter of time before a tragic incident occurred.”

Detectives said the teenager posted photos of himself posing with the firearms on his social media accounts, according to court documents. The photos appear to have been taken in the teen’s parents’ bedroom, which is where authorities later recovered the weapons, authorities said.

One photo shows the barrel of a semiautomatic rifle protruding from what appears to be a mandolin case that was being worn as a backpack, according to court documents. The photo’s caption read: “U’d never expedct it.”

The suspect has been charged with attempted threat to bomb or injure a school, second-degree unlawful possession of a firearm and unlawful possession of fireworks. He has been ordered held in secure detention while he awaits trial, court documents show.

As of Tuesday morning, the teenager’s parents did not face any charges, Cappetto told NBC News. She said authorities are still conducting interviews and that it will ultimately be up to the prosecutor to decide whether the parents will face charges of improper storage and safekeeping of firearms or any other crimes.

The teenager was last enrolled in the Franklin Public School District in 2021, according to the sheriff’s office.

Cappetto said the sheriff’s office continues to investigate and will release more information as it becomes available.