A police helicopter equipped with a special thermal imaging camera picked up on Boston Marathon bombing suspect Dzhokhar Tsarnaev's body heat through plastic covering on a Watertown resident's boat, and helped in the arrest.
State troopers showed the camera and the helicopter to members of the press on Friday at the Massachusetts State Police Airwing at the Plymouth Airport.
"With the camera that we had, we were able to look right through the plastic as if it wasn't even there," said Massachusetts State Trooper Ed Mathurin.
Mathurin was part of a three-man chopper team which included trooper Eric Fairchild and piloted by Trooper Mark Spencer.
"We were excited that hopefully we had finally come to a conclusion to this," Spencer said.
The camera on the front of the helicopter was operated from inside the cabin. The device was able to see through the plastic covering and was able to track the subject while hovering above.
"He was kind of in the middle of the boat. And he was kind of looking up with his hands. It was the perfect silhouette of a human being," said Mathurin.
Despite the helicopter and its special camera, troopers concede it was a collective effort and that if it wasn't for the citizen who made an initial 911 call, things could have been much worse.
"We were a very small cog in a huge wheel. If it wasn't for the citizens and all the law enforcement agencies working together, this wouldn't have come to the conclusion that it came to," Fairchild said.