Incredible Thermal Imaging Video Of Dzhokhar Tsarnaev In Hiding

We previously saw the stunning thermal images that helped police confirm that Boston Marathon bombing suspect was indeed hiding in a boat, under a tarp. Now, the raw video of the camera in action has been released. It's absolutely mesmerising.

The three-minute video shows off footage captured by the Massachusetts state police's forward-looking infrared (FLIR) cameras, much of which is familiar from the stills released yesterday. But watching the footage in action is another experience entirely. Not only can you see Dzhokhar Tsarnaev's heat signature glowing like something out of Cocoon, you can follow one of the most tense parts of the entire ordeal: the removal of the tarp to reveal the terrorism suspect inside, and the deployment of flashbang stun grenades about around 2:20.

As we've discussed previously, FLIR cameras come equipped with special sensors that can detect infrared radiation, such as that caused by a heat source. Specifically, in this case, caused by a heat source belonging to a human body. FLIR cameras have the added benefit of being able to see through smoke, fog and other barriers. Including tarps.

The Massachusetts state police had theirs mounted to a Eurocopter AS-355N Twinstar, which is equipped with GPS synchronised mapping, interoperable communications equipment and a digital video downlink system in addition to the FLIR.

There's nothing particularly new about FLIR imaging; the first prototypes were developed back in the late '50s, and they've been used on a larger scale for the last 40 years or so. But to see it applied in this context -- and to effectively relive the end of last week's harrowing manhunt -- is to have a newfound appreciation for and old piece of technology, and of the people who use it effectively in our times of greatest need.