flexible. reporter: and john brenn sai on fox news sunday he was questioned four hours and before he was read his rights and he waived his right to have a lawyer present and is still cooperating with interrogators. juliet: did he become a u.s. citizen to get training back and forth from pakistan. reporter: there are still questions about that, his motivation for becoming a u.s. citizen but the fact is he became an american citizen and he was able to travel with a passport, many times to pakistan and met with the radical pakistani taliban leaders, connected to al qaeda. on capitol hill, juliett, there is a proposal by senator lieberman, and, this proposal would give the state department the power to strip an american, involved with the terror group of their u.s. citizenship and today, the attorney general said he s not sure if the idea is constitutional. but, it is on the table and it is being considered. juliet: julie kirtz, live in washington. thanks. gregg: new proble