UCLA geographers think they have a good idea where Al Qaeda leader Osama bin Laden has been hiding. Using standard geographical tools employed to locate endangered species and fugitive criminals, they said there is a high probability that Bin Laden has been hiding in one of three buildings in the northeastern Pakistani city of Parachinar.

“He may be sitting there right now,” said UCLA’s Thomas W. Gillespie, who led the study.

Their study relies on two geographic principles used to predict the distribution of wildlife. The first, known as distance-decay theory, holds that as an animal – or person – moves away from its preferred habitat, the probability of finding a compatible environment decreases exponentially.

The second principle, called island biogeographic theory, holds that the animal or person is most likely to move into the largest, closest area that can fulfill all its needs.

Gillespie and his students started with a satellite map centered on Bin Laden’s last known location, in Tora Bora, in eastern Pakistani border. The group eliminated areas in Afghanistan because they were under the control of U.S. forces at the time of Bin Laden’s disappearance. Then the group evaluated the cities and towns in the remaining territory and calculated the likelihood that Bin Laden would have relocated to them.

They concluded that he must have trekked nearly 2 miles over mountainous terrain to the Pakistani tribal area of Kurram and settled in Parachinar, the largest city in the region, with a population of half a million.

The class zeroed in further by searching satellite images for buildings with walls at least 10 feet high (for safety), at least three rooms (to house Bin Laden’s bodyguards) and electricity (to power his kidney dialysis machine), among other features.

In the end, they settled on two compounds that are thought to be residences, and a third, with towers on the corners, that may be a prison or an army officers club. The final answer can be found only when all this is checked against ground truth, the getting of which is the hardest part, according to Gillespie.

Such techniques have been used to capture lesser criminals, including Raymond Lopez, who committed 139 burglaries in Orange County between 2003 and 2005, said Kim Rossmo, director of the Center for Geospatial Intelligence and Investigation at Texas State University.

One conclusion the group is fairly confident about is that Bin Laden is not living in a cave. A cave would have to have a sealed entrance, be heated and ventilated, and have supplies trucked in regularly. Those physical features could be easily detected from space, they said.