out a mile long killing spree on a new york city bike path officially charged on federal terrorism charges, including providing support to isis. >> he appears to have followed almost exactly to a t the instructions that isis has put out. >> authorities revealing chilling new details about how 29-year-old saipov became radicalized while living in the u.s. prosecutors say he began plotting the attack one year ago. >> saipov allegedly admitted that he was inspired to commit the attack by the isis videos he watched. >> reporter: the criminal complaint says he was inspired by al baghdadi. his cell phone was recovered at the attack site. he waived his miranda rights and told him he chose halloween because he thought more people would be on the street and wanted to inflict maximum damage against civilians.