Keeping close track of expenses is part of al-Qaida's DNA, say multiple experts, including FBI agents who were assigned to track the terror group in the years just after its founding.
This habit, they say, can be traced back more than three decades to when a young Osama bin Laden entered King Abdul Aziz University in Saudi Arabia in 1976 to study economics, and went on to run part of his millionaire father's construction company.
After he was exiled to Sudan in 1992, bin Laden founded what became the country's largest conglomerate. His companies and their numerous subsidiaries invested in everything from importing trucks to exporting sesame, white corn and watermelons. From the get-go, bin Laden was obsessed with enforcing corporate management techniques on his more than 500 employees, according to al-Qaida expert Lawrence Wright, author of a well-known history of the terror group. Workers had to submit forms in triplicate for even the smallest purchases — the same requirement bin Laden later imposed on the first al-Qaida recruits, he said.
In Afghanistan, detailed accounting records found in an abandoned al-Qaida camp in 2001 included salary lists, stringent documentation on each fighter, job application forms asking for level of education and language skills, as well as notebook after notebook of expenses. In Iraq, U.S. forces recovered entire Excel spreadsheets, detailing salaries for al-Qaida fighters.
"People think that this is done on the back of an envelope. It isn't," says Dan Coleman, a former FBI special agent who was in charge of the bin Laden case file from 1996 to 2004.
One of the first raids on an al-Qaida safe house was led by Coleman in 1997. Among the dozens of invoices he found inside the operative's home in Kenya were stacks of gas station receipts, going back eight years.