The U.S. forces who killed Osama bin Laden in his Abbottabad compound were more than expert marksmen. Some of them were forensics experts as well, using sophisticated tools to ensure that they got the right man.

Speaking at a White House briefing, counterterrorism adviser John Brennan said he had “99 percent” certainty the commando team killed bin Laden, thanks to “facial recognition, [his] height, [and] an initial DNA analysis.”

The initial DNA analysis appears to have been done far from the scene, by “CIA and other specialists in the intelligence community” on Monday, according to an i...