It began with a detainee. According to US officials, Khalid Sheikh Mohammed, mastermind of the 9/11 attacks, gave interrogators the pseudonym of a man he described as Osama bin Laden’s most trusted courier. This person was also a protégé of Mr. Mohammed and a trusted aide of Abu Faraj al-Libbi, a former Al Qaeda number three who was captured in 2005.
“They indicated he might be living with and protecting bin Laden,” said a senior administration official at a background briefing for reporters.
But they did not know this person’s real name. For years, US intelligence searched for him in vain.
Then, four years ago, they uncovered his identity. US officials won’t say how this was done. It took two more years of persistent effort to figure out in which areas of Pakistan the courier and his brother worked.
Still, US analysts could not figure out exactly where this courier lived. His tradecraft – measures taken to guard his own security – was too good.
But the care he took to cover his tracks led analysts to believe that he was doing something very sensitive for the Al Qaeda organization.
Last August, the US finally identified his home – and they were shocked when they did. It was a compound in Abbottabad, Pakistan, about 75 miles north of Islamabad. The house was large – about eight times larger than the average for the area. It was surrounded by 12- to 18-foot walls topped with barbed wire. Internal walls sectioned off different areas of the compound.
“The physical security measures of the compound are extraordinary,” said a senior administration official.