April 3 (UPI) -- Pennsylvania police found more than 1,600 rounds of ammunition and a 9 mm handgun while searching the home of an 18-year-old exchange student accused of threatening an attack at his high school.
According to police, An Tso Sun, a student at Bonner Prendergast High School, used parts he bought online to build the gun himself.
Investigators said the 18-year-old foreign exchange student from Taiwan, who was arrested last week, had told a classmate at Bonner Prendergast High School not to come to school May 1 because he had planned a shooting spree that day. The classmate told a teacher, who called police.
According to Upper Darby, Pa., police, An's school-issued iPad showed he had searched at least 20 times how to buy an AK-47 or an AR-15 semi-automatic assault rifle and gun parts.
After getting a search warrant Tuesday, police said they went to the home of An's host family and found 663 rounds of 9 mm ammo, 425 rounds for an AK-47, nearly 300 for an AR-15 and 225 shotgun rounds. The hand-assembled gun had been removed from the student's room.
Police say An legally obtained all of the weaponry, which was discovered inside a duffel bag removed from his room prior to authorities arriving for the search.
An was is being held on a detainer by U.S. Immigration and Customs Enforcement.