as a student in the classroom. >> reporter: still, the emerging picture is unsettling. he was in the u.s. on a work visa, a year ago, he took the oath of american citizenship. then five months later, according to court records, he admitted having traveled to pakistan and in fact just last february, an immigration inspector at kennedy airport in new york stopped him. authorities said shahzad told him he had been in pakistan for five months visiting his parents, said he was planning on staying in a motel in connecticut while he looked for a job and place to live. he told him his wife was back in pakistan, although something about his travel profile at the time set off red flags. for example, we know he bought a one way ticket for the flight and paid for it in cash. >> without getting into a lot of detail, he was screened when he came back because of some of the targeting rules applied. >> reporter: what we now know is shahzad admits he had bomb making training in pakistan on