But Zawahiri scuttled the plot, saying, "We have something better in mind," former CIA Director George Tenet wrote in his 2007 autobiography. Five years later, the U.S. government still does not know what "better" device Zawahiri was referring to, said Quillen and the senior U.S. intelligence official.
Abu Khabab also developed "contact poisons" that could be rubbed on a doorknob or some other common area, and experimented with adding crushed glass to the mixture to help get it into a potential victim's bloodstream, a former WMD case officer at the CIA said.
In recent years, Abu Khabab also began lobbying for more funding to pursue what he claimed would be a successful program to build a nuclear device, according to the former CIA officer and other U.S. officials familiar with the intelligence.
"He has for years told Al Qaeda that he could do it, 'Just give me the money,' " said the former CIA officer, who spoke on the condition of anonymity because of rules preventing former agency officials from discussing details of specific cases. "He's full of crap. He can't. But he can certainly build a good RDD" -- a radiological dispersal device.
Also known as "dirty bombs," radiological dispersal devices have conventional explosives wrapped around radioactive material. When detonated, they can cause some injuries, and potentially widespread contamination and tremendous psychological and economic damage.
In June 2004, the U.S. government had tracked Abu Khabab to Pakistan and issued a $5 million reward for information leading to his capture. The wanted poster said he had been distributing training manuals for making chemical and biological weapons.
In January 2006, U.S. officials caught wind of a purported meeting in Damadola, near the Afghanistan border, that Abu Khabab and other senior Al Qaeda operatives, maybe even Zawahiri, were to attend.
The CIA fired Hellfire missiles from Predator drones at the site, killing as many as 18 people, including at least 13 civilians. Soon after, Musharraf said a son-in-law of Zawahiri and Abu Khabab were among the dead.
Despite Musharraf's claims, the CIA concluded several months later that Abu Khabab was alive, based on evidence from human intelligence and electronic intercepts of conversations in which people talked about him in present tense.
The CIA dispatched additional agents into northwest Pakistan in the summer of 2006, including one specifically responsible for finding Abu Khabab, who officials believe had gone deep into hiding, communicating only by courier.
"I and many other CIA people considered [him] particularly dangerous, given his portfolio for Al Qaeda," said Arthur Keller, one CIA case officer sent to the tribal areas to track Al Qaeda.
"I would have been happy to help him on his way to paradise by any available means," said Keller, who left the CIA later that year, "but the opportunity never arose."
josh.meyer@latimes.com
--
Times staff writer Laura King in Islamabad, Pakistan, contributed to this report.
