There would be enough in a lock of hair. In some rare cases, it's used for criminal identification but it only narrows things down to a single family. With most criminal cases, that's often all it takes. Most families only have one black sheep (or they're a flock of them, but we won't go there). Robots don't need this though, because they extract confessions with steel claws and terror!
See also: "Forensic Evidence: Science and the Criminal Law, Second Edition." Most of it's on Google Books. It has a couple case studies that are quite boring! See pages 106-119.
As for TALON and other robotic weapons systems, I think it's only a matter of time before the Russians or Chinese figure out a way to jam wireless signals or even worse, take control of the robot. That's going to be a very fun arms race!