After weekend arrests made in Colorado and Queens, the FBI says it prevented a terrorist attack in New York City. Authorities arrested the plot's suspected ringleader, Najibullah Zazi, a 24-year-old airport shuttle driver, in Denver on Saturday night. Zazi's father, Mohammad Zazi, was also taken into custody, and both are expected to appear in court in Denver on Monday. Zazi had been under surveillance by the FBI and CIA for a year leading up to his arrest, and allegedly traveled to Pakistan twice for al Qaeda explosives training. Nine handwritten pages detailing the manufacture and detonation of explosives were found in Zazi's possession, according to the FBI. The FBI also arrested Ahmed Afzali, an imam in Queens who allegedly made false statements to officials about his contact with the Zazis. He is also due in court Monday morning.