So where is bin Laden?
ART KELLER, FORMER CIA OFFICER: The working presumption was somewhere in the tribal areas of Pakistan.
COOPER: Art Keller is a former CIA officer who spent time last year hunting bin Laden in the Afghan/Pakistan border region. The smart money says bin Laden is still there, along with his deputy, Ayman al-Zawahiri, but it's just a guess.
KELLER: They're both very tough nuts to crack. I think they have really good operational security and they are cognizant that they are high value targets number one and two.