Peter L. Bergen

As the 20th anniversary of the Sept. 11, 2001, attacks approaches, a new biography by journalist Peter Bergen traces Osama bin Laden's path from a shy, religious teenager to the leader of a global jihadist group dedicated to mass murder.

Journalist Peter Bergen outlines the decade-long search for the al-Qaida leader in his new book Manhunt. Bergen is the only journalist to gain access to bin Laden's Abbottabad compound before it was razed by the Pakastani government.

CNN's national security analysts Peter Bergen just returned from Pakistan, where he just returned from Pakistan, where he visited the town where Osama bin Laden was killed. He talks about the various conspiracy theories surrounding bin Laden's death -- and how al-Qaide has changed in recent years.