Taiwan teen who ‘threatened’ to shoot up American high school built his own gun

More than 1,600 rounds of ammunition were also found in his bedroom

A Taiwanese exchange student in the United States was arrested last week after threatening to “shoot up” his Pennsylvania high school. 18-year-old An Tso Sun claimed that he was just joking about the threat. However, in their investigation, local police have made some troubling discoveries.

Using parts bought online, Sun had managed to build his own 9mm handgun, Upper Darby Police Superintendent Michael Chitwood said at a news conference earlier this week.

Chitwood said that the homemade gun was found inside a duffel bag, along with 1,600 rounds of ammunition for various types of firearms — 225 rounds of 12-gauge ammo, 663 rounds of 9mm ammo, 295 rounds of AR-15 ammo, and 425 rounds of AK-47 ammo.

“In my opinion, based on the totality of everything, we certainly feel he was going to shoot down the school,” Chitwood said.

Sun was arrested last week on charges of “making terrorist threats” for allegedly planning an attack on his Monsignor Bonner Archbishop Prendergast Catholic High School on May 1st.

After the arrest, police searched Sun’s bedroom in the home that he was staying at in the town of Lansdowne, finding a high-powered crossbow, a military-style ballistic vest, ammunition clip pouches, a garrote, a military ski mask, 20 rounds of 9mm ammunition, and the duffel bag.

Sun’s defense lawyer, Enrique Latoison, said that many of those items were simply props for a school Halloween costume contest. A photo on Facebook from October shows Sun dressed up in military gear.

Other photos of Sun dressed in military-style gear have also popped up online.

Friends have described Sun as a military hobbyist who wouldn’t hurt a fly and had simply made an inappropriate, dark joke. He is the only son of Sun Peng, a famous Taiwanese TV presenter and actor, and Di Ying, a Taiwanese opera singer and actress. They have both proclaimed their son’s innocence and flew to the US last week to see him jail and organize his defense.

Last Thursday, Tuo Tsung-kang, a Taiwanese TV personality who co-hosts a talk show with Sun Peng, also spoke out in defense of his colleague’s son, declaring that he had watched An Tso Sun grow up and could never imagine that the well-mannered and polite boy would shoot up a school.

Tuo explained that Sun’s hero was Lee Chang-yu, a famed Taiwanese-American forensics scientist. Sun hoped to follow in Lee’s footsteps and enroll at an American university to study criminal psychology, Tuo said.

“The entire thing is a huge misunderstanding…he [An Tso] is simply not that kind of person,” Tuo added.

A hearing on Sun’s case is scheduled for April 11th. Department of Homeland Security officials are now helping local police with their investigation into Sun.

Last week, a Chinese student at the University of Central Florida also made headlines after it was announced that he was to be deported following displays of “disturbing” behavior that included buying high-powered guns.

The former student, 26-year-old Sun Wenliang purchased the guns legally, however, it was discovered that he was not actually attending classses, meaning that he was in violation of the terms of his US visa. With his student visa revoked, Sun was now breaking the law for owning a pair of rifles.

He was shortly arrested, and, in late March, an immigration judge decided that he should be deported back to China forthwith.

Sun Wenliang and one of his guns.