Judy and Marc Ehrlich watched the marathon from a spot between miles 25 and 26 on Monday and felt the ground shake when the bombs exploded. The couple said it was creepy to see images of the suspects who were there at the same time, walking around. But they were comforted that the FBI had come up with suspects.
“Unless they kill themselves, they’re going to get found,” Marc Ehrlich said. He added: “There’s nowhere in the world to hide.”
James Kallstrom, who headed the FBI office in New York City in the 1990s, said “you get a million phone calls” when the public is asked for help. But “that’s why you have 1,000 people working for you.”
“The key is to have a good filtering system. There’s going to be a whole bunch of these things you just disregard,” he said.
At the Cathedral of the Holy Cross earlier in the day, Obama saluted the resolve of the people of Boston and mocked the bombers as “these small, stunted individuals who would destroy instead of build and think somehow that makes them important.”
“We will find you,” he warned.
Seven victims remained in critical condition. Killed were 8-year-old Martin Richard of Boston, 29-year-old restaurant manager Krystle Campbell of Medford, Mass., and Lu Lingzi, a 23-year-old Boston University graduate student from China.
The large volume of video and photos gathered as part of the investigation is being examined and enhanced by a special FBI unit. Investigators are looking at video frame by frame — a laborious process, though one aided by sophisticated facial-recognition technology and other software, forensic specialists said.
Investigators can set the software to search for certain types of objects or people matching a height and weight description. The software can also spot patterns that human analysts might not notice, such as a certain car that turns up in different places, said Gene Grindstaff, a scientist at Intergraph Corp., a Huntsville, Ala., company that makes video analysis software used by the FBI and other law enforcement agencies.