Video takes down Boston bombing suspects

Looking back on it, it was a little too close for comfort: Walking the streets of Cambridge at about the same time the Boston Marathon bombers were killing a police officer at MIT, just a few blocks from a nightclub where I was heading with a friend. Investigators had released photos of the suspects a few hours earlier and they were now on the run, with a carjacking, police chase (more on that later) and shootout to follow.

The two men should have known they wouldn't remain anonymous for long. Given the extent of video surveillance at the bombing site and the number of people taking photos of the race on their cellphones, it was only a matter of time before authorities put the pieces together. Credit for identifying the suspects goes not only to the police and FBI, but also to the technology that made it happen.

The use of that technology extended to the arrest of Dzhokhar Tsarnaev, the suspect who fled on foot after surviving the shootout on the night of April 18. Holed up in a shrink-wrapped boat in Watertown, his presence was confirmed by helicopter with the help of thermal-imaging cameras provided by FLIR Systems.

In a black-and-white image that has gone viral since Tsarnaev was taken into custody, his glowing body can be seen through the covering on the boat. Police later sent in an unmanned vehicle to lift the covering, which allowed them to determine that Tsarnaev was not wearing an explosive vest. They soon moved in and apprehended him, ending four days of high anxiety.

My night in Cambridge ended with an improvised escape from town. After leaving the club we found the streets buzzing with dozens of police cruisers, all screaming west toward the shootout in Watertown. Think of the chase scene from “The Blues Brothers” movie—no intersection was safe to cross, even if you had a green light. The main routes out of Cambridge were blocked, so we had to pick our way through a maze of side streets until we found our way home.

What we didn't know that night was that the MIT slaying and the bombing suspects were connected. That information was confirmed after we made it out of the city, which was soon under lockdown. I'm not sure I would have changed my plans, but I'm obviously glad our paths didn't cross.