Inside the groundbreaking science used to identify 9/11 remains

First the fragments have to be meticulously ground up — the finer the better. Scientists had to crush bones to dust by hand with a mortar and pestle until they came up with a better system to pulverize the remains using metal ball bearings and ultrasonic vibrations.

Then, an enzyme that triggers DNA replication is added to the mix to improve the yield on what little genetic material they can extract from the bones.

“We’ve been able to develop our own procedure here in New York City,” Desire said. “So these techniques have allowed us access to more cells and the more chances we have at getting usable DNA.

“We’re further in the future because of the World Trade Center — forensic science is — than we would have been without.”