Following the courier

Osama bin Laden avoided detection for nearly a decade by relying on a network of couriers -- rather than phone or e-mail -- for communication. Here is a look at how intelligence officials pinpointed the messenger who unknowingly led them to bin Laden, and what transpired after they located the founder of al-Qaeda:

March 2003

Khalid Sheik Mohammed captured by intelligence officers. He gives authorities the nicknames of several bin Laden couriers. Abu Faraj al-Libbi takes over as bin Laden's No. 3.

July 2003

Libbi receives a letter from bin Laden's "designated courier" stating that he will be the "official messenger" between bin Laden and others in Pakistan. Libbi moves his family to Abbottabad.

May 2005

Libbi is arrested by Pakistani Special Forces. He is turned over to the CIA and is kept in a secret prison until 2006, when he is transferred to Guantanamo Bay, Cuba.

2007

U.S. officials learn the identity of a courier who could be living with bin Laden. A protégé of Mohammed, the man was an assistant of Libbi.

August 2010

U.S. intelligence identifies a residence in Abbottabad where the courier and his brother are living.

Sept. 2010

CIA tells President Obama about the compound and that a key al-Qaeda operative appeared to be harboring a "high-value target."

March 14, 2011

Obama holds the first of five National Security Council meetings to discuss how to proceed.

Early April

A Navy SEAL team uses a replica of the compound and begins trial runs of operations to kill or capture bin Laden.

April 29

Obama authorizes the operation before flying to Alabama to inspect tornado damage.

May 1

Obama announces that bin Laden was killed earlier in the day.

GRAPHIC: Laris Karklis, Julie Tate and Karen Yourish - The Washington Post. Published May 3, 2011.