Osama bin Laden was shot twice in the head, but it appears his face was intact, allowing the US forces to use cutting-edge face-recognition technology to establish the preliminary identity.
Even this 95% identity match wasn’t enough. The US military had to delve into Osama’s genes to provide a 99.9% match.
The US government used face-recognition to first spot bin Laden — or at least someone who looked like him — in satellite pictures taken during September 2010, as the al Qaeda founder exercised in his Abbottabad compound in Pakistan, the Associated Press reported.
While the ability to spot a person from a satellite orbiting the earth was previously believed to exist only in the movies and helped find Osama, face-recognition was less useful in conclusively proving that it was him.
Facial-recognition works by mapping various points on a face to create a biometric fingerprint. Even with the living, facial recognition poses some problems; with the dead it can get tricky.
A facial image from a slightly different angle will alter that biometric fingerprint. An image of a face that has lost some mapping point — such as an eyeball or disfigured nose, all possibilities during a gunfight — reduce the probability of a match.
A 95% match of identity is the top end of the scale, a facial-recognition expert in an Indian intelligence agency told Hindustan Times, requesting anonymity for him and his organisation.
This suggests Osama’s face was intact. But a 95% match was never going to be enough, given the questions the killing would immediately spawn.
So, as John Brennan, assistant to US President Barack Obama for homeland security, later explained, DNA — deoxyribonucleic acid, the blueprint for life, encoded in bits of DNA called genes — evidence provided a match with “99.9% confidence.”
This implies the US either had Osama’s DNA samples or access to one of his children. DNA provides a unique personal pattern that can be matched with confidence to brothers or sisters. Osama had only half brothers and sisters — more than 50 — and while matching samples with them can provide a DNA match greater than 90%, this too wasn’t enough.
The genetic analysis of DNA from half brothers and sisters is complex and not as reliable as DNA from a parent or child. With one of bin Laden’s sons reportedly killed in the raid (that may have been 20-year-old Hamza bin Laden), it could be possible that the US military used his DNA and, in addition, matched it with previously gathered samples from Osama’s half-brothers and sisters scattered across the world.
It is also possible that US forces had obtained Osama’s DNA from a previous hideout, perhaps a strand or hair or drop of blood. Every part of the human body can provide DNA — and thus an identity more distinctive than a fingerprint.