paterson, new jersey. they don't know when he was radicalized in the united states. what is your best take on when he was radicalized? >> online and offline radical sayings and they hang out with people who embrace isis views. many cases, people radicalized because they have some personal issues, whether it could be family problems or, you know, job problems. >> reporter: this expert says the process of becoming radicalized means spending a lot of time online. >> now it's apps. very easy to download on your phone. most encrypted and you can get all sorts of information. you can interact with other people and you can run commitment to isis and get operational instructions. >> reporter: official believe saipov had close familiarity with operational instructions. >> he appears to have followed, almost exactly to a tee, the