“Heavily armed law enforcement officers swarmed the Philadelphia home of a teenager who was plotting to launch a national terrorist attack, authorities said. The suspect, an unnamed 17-year-old, was in contact with a global terrorist group affiliated with al Qaeda and had access to a "significant" number of guns and was building bombs, FBI Special Agent in Charge Jacqueline Maguire said during a Monday press conference. The teen, who was arrested Friday, "conducted general research" into potential targets that weren't confined to one location, and they were not just in Philadelphia, she said. "Most concerning was the evidence to his access to firearms and purchased items and materials commonly [used] for constructing improvised explosive devices," Maguire said. "Among the items he purchased were tactical equipment, wiring, chemicals and devices often used as the detonators."