PLYMOUTH — Suddenly, there he was, a perfect infrared silhouette: accused Boston Marathon bomber Dzhokhar Tsarnaev crouched in the center of a boat in a Watertown driveway, surrounded by officers with guns drawn as the State Police Eurocopter TwinStar helicopter hovered above.

“At the moment, you don’t have the time to process it,’’ said Trooper Mark Spencer, who piloted the copter, at a news conference about last Friday’s dramatic capture. “Later is when it sinks in. … We still say, ‘Did that really happen?’’’

Spencer was one of a three-man flight crew, which also included Troopers Eric Fairchild and Edward Mathurin, who watched Tsarnaev from the sky on April 19 and gave second-by-second updates to officers on the ground about the suspected terrorist’s every move. The three spoke at a news conference today at the State Police Air Wing hangar in Plymouth.


Police did not know if Tsarnaev was armed, and the flight crew was able to keep officers apprised of what he was doing as he sat up and lay down in the boat throughout most of the one and a half hour standoff that began around 7 p.m.

“Moving hands is what could hurt incoming officers,’’ said Fairchild.

Tsarnaev, 19, and his 26-year-old brother Tamerlan allegedly planted two bombs at the finish line of the Boston Marathon, killing three and wounding hundreds. Dzhokhar Tsarnaev was discovered by a Watertown homeowner hiding underneath a tarp in the boat after a 20-hour manhunt that began the night before, when the brothers allegedly shot an MIT police officer to death and engaged in a gunfight with police, during which Tamerlan was killed.

On Friday, the troopers said, they dealt with a flood of false alarms from a jittery public, and had been flying over suburban streets and backyards in their helicopter, with its forward-looking infrared camera used to record heat images and its 3 million candlepower Night Sun searchlight.

They were just two miles away when the call came in: A woman at 67 Franklin St. in Watertown said there was blood on the boat parked in her driveway.


It took only minutes to fly to the home and find their man.

“We were there like that,’’ said Mathurin, snapping his fingers. “We do this day in, day out. This is what we do. We went over and when I put that [infrared camera] on the boat, I was actually shocked that not only did I see there was a heat source, but I got a perfect human silhouette. That doesn’t happen that much.’’

All three said their training kicked in — they did not feel fear, only determination to keep the officers on the ground safe and informed of what Tsarnaev was doing.

They flew in tight circles about 1,200 feet overhead — usually, said Spencer, they would hover to make it easier to aim the camera, but they did not know if Tsarnaev had a gun, and did not want to make themselves a stationary target. (It turned out that Tsarnaev did not have a gun.)

Spencer said it was important for the officers on the ground to hear the blow-by-blow of Tsarnaev’s movements because it was a tense situation with police pouring into the area, and having a calm, running update on the suspect’s movements kept the adrenaline from spiking.

The three men said they did not pause to consider how surreal it was to be hovering over a suspected terrorist in a boat in a suburban neighborhood with the eyes of the world watching until afterwards, when low fuel forced them to leave the scene and land at Logan International Airport.


“Then,’’ said Fairchild, “we went, ‘Wow. Wow.’’’