U.S. officials said that a CIA team is expected to arrive at the compound in Abbottabad, Pakistan, within days and that the objective is to scrub the site for items that were not recovered by American commandos during the raid early this month or by Pakistani security forces who secured the facility afterward.
“The assault team was there for only 40 minutes,” a U.S. official said. The aim is to return to the site “to do another, more thorough look.” The official, like others interviewed, spoke on the condition of anonymity to discuss intelligence matters.
CIA Deputy Director Michael J. Morell negotiated access to the Abbottabad site during a trip to Islamabad last week, when he met with Lt. Gen. Ahmed Shuja Pasha, the head of Pakistan’s main intelligence service, officials said.
Pakistan’s agreement is considered an encouraging sign that the two spy services will continue cooperating despite anger in Islamabad about the American operation to kill bin Laden and a series of recent ruptures between the CIA and its Pakistani counterpart.
Pakistan has also agreed to allow the CIA to examine materials that Pakistan’s security forces hauled away from the compound in the days after the raid, officials said.
In turn, the CIA has asked Pakistan’s spy agency, known as the Inter-Services Intelligence directorate (ISI), for assistance in analyzing some of the records that were seized and brought to a CIA document exploitation facility in Northern Virginia.
In particular, U.S. officials said the CIA is seeking help with deciphering references to names of people and places. The agency has turned to the ISI for help identifying and locating people who were seen entering and leaving the compound during the months it was under near-constant American surveillance.
U.S. intelligence officials have described the materials from the bin Laden compound as the largest intelligence haul ever recovered relating to a terrorist network. The materials include dozens of computer storage devices as well as thousands of pages of documents.
Even so, U.S. officials said they want to be sure that other material has not been overlooked. The CIA plans involve the use of infrared cameras, X-ray equipment and other devices capable of identifying items embedded behind walls, inside safes or under floors.
Pakistan agreed in part because it does not have comparable equipment, officials said, and was convinced that more intrusive search methods — such as breaking through portions of the structure — might risk destroying any items hidden inside.
U.S. intelligence officials have said they think that bin Laden became remarkably complacent during the years he spent in hiding at the compound and appeared to have no plan to escape or destroy sensitive materials as commandos made their way toward his upstairs room.
Still, CIA veterans said that an exhaustive search was warranted, given bin Laden’s importance to al-Qaeda and the risk of overlooking even minute clues to the whereabouts of other senior leaders in the network.
“Even if he got very complacent, you would think he still would have had some sort of hiding area or safe, like [most people do] at home,” said a former senior CIA official who had been involved in the pursuit of bin Laden. “You wouldn’t do it for every run-of-the-mill high-value target, but you would do it for him.”
In addition to searching the compound for a vault, CIA experts are likely to collect swab samples of surfaces in bin Laden’s living area to look for clues.
DNA material could show whether Ayman al-Zawahiri, al-Qaeda’s second in command, or other senior figures visited bin Laden. Clothing samples sent to U.S. labs could determine whether bin Laden came into contact with chemical or biological agents that he directed al-Qaeda to pursue.
Even a substance as innocuous as pollen could provide information about where bin Laden or visitors had traveled in Pakistan, the former CIA official said.
The agency also has equipment that could be used to recover information that has been burned or otherwise damaged. U.S. officials have said that residents burned their trash inside the compound’s walls.
The CIA deployed similar forensics teams to Afghanistan after the attacks of Sept. 11, 2001. The agency’s experts are part of its Directorate of Science and Technology, although the CIA frequently turns to other agencies, including the FBI and the Energy Department, for some technical capabilities.
U.S. officials said they have seen no evidence that there were tunnels beneath the compound.
One official said the CIA concluded before the raid that any underground escape routes for bin Laden were unlikely to exist because a high water table in Abbottabad probably would submerge passageways under the compound walls.
The CIA has been given access to three of bin Laden’s wives who were taken into custody by Pakistan after the raid. But officials said none of them has cooperated with U.S. interrogators or provided meaningful intelligence.
The agreement on the compound followed what U.S. officials described as a frank and productive discussion between the ISI director and Morell, who is in line to serve as interim director of the CIA if Leon Panetta is confirmed as defense secretary.
Morell’s trip was also aimed at repairing a relationship that has appeared on the verge of collapse in recent months. Recent ruptures include Pakistan’s arrest of a CIA contractor who fatally shot two Pakistani men in Lahore, as well as U.S. suspicions that the ISI deliberately exposed the identities of two undercover CIA operatives in the past six months.
Pakistani news accounts suggested that Pasha used his meeting with Morell to reiterate demands that include a dramatic reduction in the number of drone strikes.
The U.S. official declined to comment on the matter but said that despite signs of progress — such as Pakistan’s decision to return the U.S. helicopter damaged in the raid — the two spy agencies are proceeding warily.
Agreeing to grant the CIA access to the compound “is another good sign,” the U.S. official said. “But there’s still some issues to sort out.”
Correspondent Karin Brulliard in Islamabad contributed to this report.