Ask any soldier whose been involved with IEDs in Iraq and Afghanistan, and I guarantee you they'll be able to tell you that there will be at least SOMETHING nasty left over that you can get DNA from.

The FEDs will say they found whatever is convenient for them, even if it has to be manufactured. They will also ignore what they find if it is inconvenient for the Uniparty.

Plane engines and cockpit incinerated but a piece of laminated paper survives ....