WASHINGTON — When President Trump announced on Sunday morning that a Special Operations forces raid had resulted in the death of the Islamic State leader Abu Bakr al-Baghdadi, he said two things that might have sounded contradictory.

One was that Mr. al-Baghdadi, cornered in a tunnel by American forces, had detonated a suicide vest and that “his body was mutilated by the blast.” The other was that, as Mr. Trump put it, “test results gave certain immediate and totally positive identification. It was him.”

Mr. Trump did not provide any details of how that identification was made. But the quick turnaround after Mr. al-Baghdadi’s violent demise suggests that American Special Operations forces made use of biometric tests and DNA technology, which has advanced significantly in recent years.

The latest DNA-testing machines, which are now used by some state and local authorities, can provide a positive identification in about 90 minutes, according to David H. Kaye, a Penn State Law School professor who specializes in the field. But military commandos also base their conclusions on several other factors, including human intelligence and, when possible, basic facial features.