04 May, 2011

How DNA analysis confirmed Osama bin Laden’s death ?

Though the world''s most wanted man Osama bin Laden was killed during a raid on a compound in Abbottabad, Pakistan, on 2 May, his body was identified after a series of investigation.

According to the US Government, his death was confirmed by comparison to photographs, confirmation from one of his wives at the compound, facial-recognition software, and - the gold standard for identification - DNA analysis, reports New Scientist.

John Brennan, assistant to the President for Homeland Security and Counterterrorism, said the DNA evidence provided a match with "99.9 per cent confidence".

That would require the comparison of DNA from the body with that of people known to be related to bin Laden. Bin Laden had no full siblings, but more than 50 half-siblings and up to 24 children.

Using DNA from many half-siblings could produce a DNA match of greater than 90 per cent confidence, but it would be difficult to get as high as 99.9 per cent without a closer relative said Rhonda Roby, a forensic geneticist at the University of North Texas Health Science Center, Fort Worth.

Roby, who led the team using DNA evidence to identify the remains of people killed in the 9/11 attacks in 2001, said that the statistical analysis based on DNA from half-siblings is more complex and less reliable than analysis based on DNA from a closer relative like a parent or child.

Reports indicated that one of bin Laden''s sons was also killed in the raid, possibly 20-year-old Hamza bin Laden.

Roby said DNA from a son and several half-siblings could confirm Osama''s identity with 99.9 per cent accuracy.

If, however, the government was able to obtain DNA from bin Laden''s body, his son and also that son''s biological mother - who might have been at the compound during the raid, it could perform DNA profiling with a "full paternity trio", assuring 99.9 per cent accuracy, she added.