After the firefight that killed Osama bin Laden, the U.S. used "multiple methods" to positively identify his remains. A senior White House official tells NBC News that the U.S. has completed the DNA analysis and it has come back with a nearly 100 percent match to his relatives. Osama bin Laden's death has been confirmed, with the DNA evidence providing a match with 99.9 percent confidence.
NBC News has also been told that the CIA'S facial recognition technology has identified bin Laden's face with 95 percent certainty -- considered a very high accuracy -- after comparing it to known pictures of him. Bin Laden was first visually identified on the scene by people in the U.S. forces team who conducted the raid, according to a U.S. official speaking on background. Bin Laden was also identified by a woman initially believed to be one of his wives, the official said.
The chairman of the House Intelligence Committee says more than one DNA sample was used to identify Osama bin Laden after U.S. troops killed the al-Qaida chief in a weekend raid in Pakistan.
Rep. Mike Rogers says there are many places where bin Laden's DNA is available, including relatives. He says the U.S. government had been preparing for such testing for some time.
The Michigan Republican, a former FBI agent, says that as a result of the DNA tests and other techniques, it is "clear beyond a shadow of a doubt" that bin Laden is the person killed in the raid.
White House officials did not immediately say where or how the testing was done but the test explains why President Barack Obama was confident to announce the death to the world Sunday night. Obama provided no details on the identification process.
The U.S. is believed to have collected DNA samples from bin Laden family members in the years since the 9/11 attacks that triggered the U.S.-led invasion of Afghanistan. It was unclear whether the U.S. also had fingerprints or some other means to identify the body on site.
It’s possible that the government collected samples from some of the places where bin Laden lived over the years, said Dr. George Michalopoulos, chairman of the department of pathology at the University of Pittsburgh Medical Center. Comparing those samples with the ones from bin Laden’s body would be the best way to identify the remains, said Michalopoulos.
“One way to identify a body is through comparison with blood samples or with DNA from a toothbrush or comb,” Michalopoulos said. “That’s extremely accurate.”
Without samples from bin Laden himself, pathologists could have identified the body in much the same way as some of the 9/11 victims were identified -- by comparing blood and tissue samples with those from close relatives.
“If you use DNA from immediate relatives such as children or parents, you can make an identification with about 95 percent accuracy,” said Michalopoulos
In the case of some of those who died in 9/11 family members were asked to supply hair samples from brushes of their loved ones, said Dr. John Tomaszewski, president of the American Society for Clinical Pathology.
If this is how bin Laden has been identified, “it’s a very ironic twist,” Tomaszewski said.
Bin Laden was shot in the head during the firefight with members of an elite American counter-terrorism unit that launched a helicopter-borne raid on the al-Qaida leader's compound in Pakistan early Monday, U.S. officials said. Officials said the U.S. special forces who stormed the compound came face-to-face with their prey.
U.S. officials also said bin Laden was identified through "facial recognition," a reference to technology for mapping unique facial characteristics, but it was not clear exactly how the Navy SEAL troops performed the comparison.
The body was later taken to an American warship, but the senior Pentagon official declined to say which one and where the ship was situated.
The body was photographed before being buried at sea, although no images have been released by the Obama administration.
The U.S. official who disclosed the burial at sea said it would have been difficult to find a country willing to accept the remains. Obama said the remains had been handled in accordance with Islamic custom, which requires speedy burial.
Positive identification of the remains is considered a critically important part of the U.S. operation, given the symbolic importance of bin Laden's leadership of the Islamic extremist movement that was based in Afghanistan until the U.S. invaded in October 2001.
When al-Qaida's leader in Iraq, Abu Musab al-Zarqawi, was killed in a U.S. airstrike in June 2006, DNA tests were performed by the FBI to positively identify the remains. The U.S. military also performed an autopsy, in part to dispel allegations in the immediate aftermath of the airstrike that the terrorist leader had been beaten or shot by U.S. soldiers while in American custody.
It was not clear Monday whether the Obama administration intended to release its photos of bin Laden's body.
In July 2003, when U.S. forces killed Saddam Hussein's sons, Odai and Qusai, in a gunbattle in northern Iraq, the U.S. military released graphic after-death photographs in an effort to prove to Iraqis that they were dead. Two of the photos showed the first man, identified as Qusai, with bruises and blood spots around his eyes. That face was far more intact than the other, identified as Odai; the mouth was open with the teeth showing.
NBC News, The Associated Press, Reuters and msnbc.com contributor Linda Carroll contributed to this report