I just saw the CNN report. Listening to this guy talk gives me doubts that he is American, or at least that the story of him being over there for only 6 months.
The local reports here in the Washington, DC area is that he grew up in the Maryland suburbs (or at least until he was 10) and then moved with his family to CA.
Todays Washington Post says that he went overseas to study Arabic several years ago.
If all this is true, then it is obvious he has been immersed into this Arab/Pakistani/Islamic culture for a number of years.