UPPER DARBY TOWNSHIP, Pa. – A school shooting appears to have been averted at a high school in Pennsylvania.

Over 1,600 rounds of ammunition and a semiautomatic firearm were found after a student was arrested for threatening to shoot up Bonner Prendergast Catholic High School in Drexel, officials said Monday.

An Tso Sun, an 18-year-old foreign exchange student from Taiwan, was arrested last week and charged with terrorist threats with the intent to terrorize another, according to Upper Darby Police.

Police Superintendent Michael Chitwood said Sun bought the parts for the firearm online and “put it together” himself, reported ABC News.

“It was a weapon capable of firing,” Chitwood said.

There was a range of ammunition seized. Among the recovered projectiles were 225 rounds of 12-gauge shotgun ammunition; 663 rounds of 9mm ammunition; 295 rounds of AR-15 ammunition; and 425 rounds of AK-47 ammunition, according to Chitwood.

In total, police said he possessed 1600 round of ammunition.

According to CBS News, the firearm assembled by Sun was a 9mm handgun.


Boxes of ammunition are seen on display during a press conference where Upper Darby Police Superintendent Michael Chitwood told the media about weapons and ammunition found to be in possession of An Tso Sun, April 2, 2018. (Upper Darby Police)

On the day of his arrest, Sun’s host mother, who has not yet been identified, reportedly packed up the ammunition and weapon, and gave them to another person, Chitwood said.

“She went back to the house and loads all the ammo and the gun into a black bag. She then takes that to another person at another location,” Chitwood said, “She didn’t give it to the police.”

Investigators recovered the firearm and ammunition last Thursday after receiving a tip. Chitwood did not disclose the location of seizure, nor did he identify additional parties involved.

As of now, the host mother has not been charged.

Last week, Sun was arrested after he told a fellow student at the Catholic high school to “not come to school on May 1” because he “was going to shoot up the school,” according to Chitwood.

Gunfight Last Night


Fortunately, that student told school officials, and police were notified.

Sun reportedly told the student he was “kidding.”

Prior to uncovering the ammunition and firearm, officials found a number of items in Sun’s bedroom, which included: a military-style ballistic vest; a high-powered crossbow with scope and light; arrows; 29 rounds of 9mm ammunition; a strangling device; a “military” ski mask; and ear protectors used when firing weapons.

“When you add it all together, it’s a major concern,” Chitwood said.

Sun is currently in custody and police are still investigating the incident.