Thermal images of boat led to Boston bombing suspect's capture

The final moments of the capture of the second Boston bombing suspect came through a deft combination of tenacity and technology. Massachusetts State Police released thermal images Saturday that were taken from a helicopter high above the scene Friday night. The black and white images clearly show the body outline of the suspect, cowering inside a boat in suburban Watertown, Boston.

Police had spent the day cutting off all avenues of escape from Watertown, so when the call came from a homeowner who had seen a torn tarp on his boat, a blood stain, and then a person crouching inside, hundreds of officers raced to the scene.

As police hustled folks in the neighborhood away to safety, a helicopter with a sensor to detect heat sources flew over the boat and ascertained that there was someone inside, and he was moving.

They also released aerial images of a robot that police sent in extending a robotic arm to lift the tarp, and view the suspect inside.