New York: The ground work for the US operation that eliminated Osama bin Laden started way back in August 2010 when CIA operatives tracked a trusted courier of the world's most wanted terrorist to a compound in Abbottabad in Pakistan.
American military and intelligence forces have been chasing the courier, whom bin Laden relied on to maintain contacts with the outside world, and the breakthrough came when the US authorities learned his real name four years ago.
It took another two years for them to locate the region from where he operated and they tracked him to the compound in Abbotabad, just an hour's drive from Islamabad.
'The New York Times' reported that CIA analysts spent several weeks in August and September, 2010 going through satellite images and intelligence reports to determine who could be living at the compound.
"By September the CIA had determined there was a strong possibility that bin Laden himself was hiding there," the newspaper quoted a senior Obama Administration official as saying.
Through intelligence reports, the US officials came to know that the mansion, believed to be built in 2005, had neither telephone nor an internet connection and that its residents even burned their trash instead of putting it on the street due to security reasons.
The paper said American officials believed that the compound was designed for the specific purpose of hiding bin Laden.
After collecting credible information, the American spies came to a conclusion that bin Laden was in fact hiding there.
This prompted President Barack Obama to give the green signal to plan a mission to go after the al Qaeda chief.
And, on March 14, Obama held the first of the five national security meeetings to discuss the plans for the operation that finally saw the killing of the 9/11 mastermind.
The final go-ahead for the operation came on Friday when Obama met his National Security Adviser Thomas Donilon and his counter-terrorism adviser John O Brennan and other senior aides in the Diplomatic Room at the White House.
"The president was traveling to Alabama later that morning to witness the damage from last week's tornadoes. But first he had to sign off on the final plan to send intelligence operatives into the compound where the administration believed that bin Laden was hiding," the report said.
Obama chose to keep Pakistan's government in the dark about the operation.
The paper said it is no surprise that the administration chose not to tell Pakistani officials. Though the Pakistanis had insisted that bin Laden was not in their country, the United States never really believed it.
American officials gave few details about the raid itself, other than to say that a firefight broke out shortly after the commandos arrived and that bin Laden had tried to "resist the assault force."
When the shooting had stopped, bin Laden and three other men lay dead. One woman, whom an American official said had been used as a human shield by one of the Qaeda operatives, was also killed.