BOSTON — Plucking a couple of blurry faces in baseball caps out of a swarming crowd, the FBI zeroed in on two suspects in the Boston Marathon bombing and shared surveillance-camera images of them with the world Thursday in hopes the public will help hunt them down.
The photos and video depict one young man in a dark cap and another in a white cap worn backward, both carrying backpacks and one walking behind the other on the sidewalk near the finish line as marathoners run by.
The man in the white hat was seen setting down a backpack at the site of the second explosion, said Richard DesLauriers, FBI agent in charge in Boston.
“Somebody out there knows these individuals as friends, neighbors, co-workers or family members of the suspects,” he said. “Though it may be difficult, the nation is counting on those with information to come forward and provide it to us.”
They looked much like typical college students, but DesLauriers described them as armed and extremely dangerous, and urged anyone who sees or knows them to tell law enforcement and “do not take any action on your own.”
The break in the investigation came just three days after the attack that killed three people, tore off limbs and raised the specter of another terrorist attack on U.S. soil. FBI photo-analysis specialists have been analyzing a mountain of surveillance footage and amateur pictures and video for clues to who carried out the attack and why.
The volume of information is likely to grow, joined now by a torrent of tips from people who think they might know the suspects. In releasing the images, the FBI gambled that useful clues will emerge, not just time-wasting leads.
Authorities are selective in putting out images of suspects because doing so risks tipping off the hunted and losing the element of surprise. But it can be a last resort when authorities hit a wall trying to identify or capture someone, analysts say. And there were immediate signs that the public was responding.
Within moments of the announcement, the FBI website crashed, likely because of a crush of visitors.
The images were released hours after President Barack Obama and first lady Michelle Obama attended an interfaith service at a Roman Catholic cathedral in Boston to remember the dead and the more than 180 wounded in the twin blasts Monday at the finish line of the 26.2-mile race.
The FBI video is a compilation of segments, altogether about 30 seconds long. The planting of the backpack, as described by authorities, was not part of the footage made public.
The man in the dark hat was dubbed Suspect 1 and appeared to be wearing sunglasses. The other, in the white hat, was labeled Suspect 2. Both appeared to be wearing dark jackets. The FBI did not comment on the men’s height, weight or age range and would not discuss their ethnicity.
“It would be inappropriate to comment on the ethnicity of the men because it could lead people down the wrong path potentially,” said FBI agent Greg Comcowich, a spokesman for the Boston FBI office.
While authorities said the information on the men began coming together over the previous day or so, agent Daniel Curtin said the FBI did not release the photos earlier because “it’s important to get it right.”
Distribution of the images brought both encouragement and unease to some Bostonians.
Jennifer Lauro of Topsfield worried that the photos might breed unease and suspicion.
“It just looks like a college kid, so I think that’s going to make people feel vulnerable,” she said. “Because it could be anybody. It looks like any kid from Boston College or Boston University or any other school.”
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.”
At the cathedral earlier in the day, Obama declared to the people of Boston: “Your resolve is the greatest rebuke to whoever committed this heinous act.”
“We finish the race, and we do that because of who we are,” the president said to applause. “And that’s what the perpetrators of such senseless violence — these small, stunted individuals who would destroy instead of build and think somehow that makes them important — that’s what they don’t understand.”
“We will find you,” he warned those behind the attack.
Earlier, Obama sought to inspire a stricken city and comfort an unnerved nation during the interfaith service, declaring that Boston “will run again” and vowing to hunt down the perpetrators of the twin blasts that brought mayhem and death to the Boston Marathon.
“If they sought to intimidate us, to terrorize us ... It should be pretty clear right now that they picked the wrong city to do it,” Obama said.
The president spoke at an interfaith service at Boston’s Cathedral of the Holy Cross, held to honor the three people killed and more than 170 injured when a pair of bombs ripped through the crowd gathered Monday afternoon near the finish line of the historic race.
“We may be momentarily knocked off our feet,” Obama said. “But we’ll pick ourselves up. We’ll keep going. We will finish the race.”
“This time next year, on the third Monday in April, the world will return to this great American city to run harder than ever and cheer even louder for the 118th Boston Marathon,” he declared.
Among those attending the service was Congressman John Tierney, whose 6th Massachusetts House District includes all of Cape Ann.
“Too many men, women and children are suffering today, mourning the loss of loved ones or facing a long recovery for themselves or their friends and family members,” Tierney said. “Our city was attacked, but our spirit will not break. We have seen citizens join together to support strangers, and we have witnessed the heroism of our first responders.”Thousands of people crammed inside and gathered outside Boston’s Cathedral of the Holy Cross for the interfaith service. The service was open to the public on a first-come, first-seated basis. People started lining up before 5 a.m. even though doors opened at 8 a.m. The line stretched at least two city blocks. A heavy police presence surrounded the cathedral in the city’s South End, and nearby streets were closed to vehicles.
Someone outside held a green flag with the words “forgiveness” and “peace” on it.
“I’m excited to be a witness to healing and grace and peace,” said Wendy Vanderhart of Arlington, associate conference minister in the United Church of Christ congregation, said as she waited to get inside the roughly 2,000-seat cathedral.