Police: Additional weapons, ammo found at home of teen who threatened Delco high school

Police have uncovered additional weapons from the home of an 18-year-old exchange student living in Delaware County.

An Tso Sun, of Taiwan, was arrested Tuesday, March 27 for threatening to shoot up Bonner Prendergast Catholic High School.

Sun later claimed he was joking about the alleged threat against the school.

Upper Darby Police Superintendent Michael Chitwood divulged the department's latest findings at a press conference Monday. Among the newly discovered items were 225 rounds of 12 Gauge ammunition, 663 rounds of 9mm ammunition, 295 rounds of AR-15 ammunition and 425 rounds of AK-47 ammunition, or more than 1600 rounds total. Authorities also uncovered a 9mm handgun.

"Kudos to the person who stepped forward and helped to avert a tragedy," Upper Darby police tweeted.

MORE: Ammo, strangling device found at home of teen who threatened Delco high school

Chitwood had previously unveiled what authorities found at Sun's residence, including a military-style ballistic vest, a web gear backpack with pouches to hold ammo clips, a type of cold weather gear, a high-powered crossbow with scope and light and seven arrows, a loading dock--or 'speed loader'--meant for holding AK-47s and AR-15s, a wooden box made for a homemade gun, 20 live rounds of 9mm ammunition, a military ski mask, ear protectors and a garrote which Chitwood describes as "a strangling device."

"He's not a nice kid who didn't understand English," Chitwood said in Monday's press conference.

Investigators say Sun also conducted searches on how to purchase guns and ammunition online using a school-issued iPad at least 20 times.

Sun, who is in the United States on a student visa, is currently being held at Delaware County Prison on $100,000 bail.

Upper Darby police will meet with Homeland Security officials Tuesday regarding the ongoing investigation.

Robert C. Keller and Michael N. Kotik, who representing Sun in the case, released the following statement:

"Our client just turned 18 in January and is a senior in high school. This young man has had no prior contacts with the courts and has been considered an affable, precocious student with no discipline or antisocial tendencies. The young man's parents have flown in from Taiwan and fully support their child. Our investigation reveals that there was no intention to terrorize or otherwise commit any criminal act. The family is concerned by the rising level of rhetoric that is being transmitted to the news media and hopes that the public will keep an open mind as all the facts and circumstances are brought forward."