Every service member gets fingerprinted during induction. The FBI keeps the prints in a special file, but a third of them aren't usable, because they are smeared or incomplete in some way, according to Armbrustmacher. The FBI discards those prints. Neither are dental records fully reliable references, especially if the individual has no fillings. Although it still uses fingerprints and dental records, DoD wanted a surer thing and settled on the emerging science of DNA fingerprinting.
Medical examiners can draw nuclear DNA samples from any part of the body.
Even severely burned bodies often will yield DNA, Armbrustmacher said. For older remains or those damaged by extreme heat, moisture or other environmental factors, researchers also can draw DNA from mitochondrion, which are tiny rod-like structures outside the cell nucleus. Most recently, mitochondrial DNA, or mtDNA, identified Air Force 1st Lt. You have many copies of mtDNA in a given cell. The majority of the collections occur when recruits arrive at induction centers.