Photographer Discusses Images Of Boston Marathon Bomb Blast

BOSTON (CBS) - A Concord man captured images of the Boston Marathon Bombings that may help in the FBI investigation of the attack.

Amateur sports photographer Ben Thorndike was working in his financial office above Boylston Street on Monday before the bomb blasts. He was snapping photos of the race from one of the office's bay windows when suddenly -- an explosion.

In Photos: New View Of Boston Marathon Bombings

"Almost momentarily when I got there, directly in front of me, right in my sight-line, the explosion went off," he said. "Just out of reflex, I had the camera on, had it in sports mode, which means I can shoot rapid-fire."

Thorndike shot a sequence of 25 photos right after the blast that shows injured and stunned victims on the ground below. But it was the behavior of one man -- seen running from the scene -- that prompted Thorndike to contact the FBI.

"His reflex is to sprint away, that really caught my eye. Everyone else in the photo is stunned, shocked and frozen," he said. "It's either someone who is badly burned, panicked and running, or they're running for another reason."

Thornidike handed the photos over to FBI investigators, who have spoken to him several times, and he hopes the images will help the probe.

"I've got so many emotions," Thorndike said of his recollection of the bomb blast at the marathon finish line. "It's going to be hard to go back and stand in that window, thinking about the people who were killed and injured below it."

The FBI did not reveal anything to Thorndike about the investigation or the running man seen in the photographs taken from his office window.

Thorndike and his co-workers fled soon after the photos were taken. All the other bay windows in the office were blown out except the one where Thorndike stood.

Extended Interview With Ben Thorndike