Armies of white-suited agents had spent many hours sifting through the evidence littering Boylston Street, climbing to nearby rooftops to make sure no clue would go overlooked. Their efforts revealed that the bombers had constructed crudely assembled weapons, using plans easily found on the Internet, from pressure cookers, wires and batteries popular at hobby shops. But investigators still did not know why. And, more importantly, they had only the haziest idea of whom to hold responsible.
It all came down to the photos, culled after a painstaking search of hundreds of hours of videotape and photographs gathered from surveillance cameras and spectators. But if they were unable to identify the men, that left the investigators with a difficult choice: They could keep them to law enforcement officers who so far had had no luck, prolonging the search and risking letting the men slip away or attack again. Or they could ask the public for help. But then, the suspects would know the net was closing in.
When they decided to release them, it would only put Bostonians further on edge.
"There was this kind of strange tension," said Brian Walker of Boston. "You walk by people and you just kind of look at them out of the corner of your eye and check them out. I was conscious that I didn't feel comfortable walking around with a backpack. It was like I just want to be safe here and everybody is kind of jumpy."
But as investigators pored over tips in the hours before the photos were made public, the city, at least, was struggling to right itself.
On Monday, the bombs had exploded just a half-block before Brian Ladley crossed the Marathon finish line. But, feeling lucky to be alive, he was out at 7 a.m. Thursday to join the line at the Cathedral of the Holy Cross, hoping to hear President Barack Obama speak at an interfaith service to honor the victims. The event was still hours away, but when tickets ran out, authorities spotted his marathon jacket and plucked him and some other runners out of line to watch the service in a nearby school auditorium.
"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 told the crowd of more than 2,000 inside the church. "We may be momentarily knocked off our feet. But we'll pick ourselves up. We'll keep going. We will finish the race."
After it ended, Ladley found himself shaking hands with the president, too awestruck to remember their conversation. But what meant the most was the camaraderie of the crowd.
"It was wonderful to have a moment with other runners and be able to share our stories," he said.
Less than a mile away, 85-year-old Mary O'Kane strained at the bell ropes in the steeple of historic Arlington Street Church, imagining the sounds spreading a healing across her city — and the land. Sprinkled amid hymns like "Amazing Grace" and "A Mighty Fortress," patriotic tunes like "America the Beautiful" and "God Bless America" wafted down from the 199-foot steeple and over Boston Common across the street.
"I feel joyful. I feel worshipful. I feel glad to be alive," she said. The city's response to the bombing had revealed its strength and brotherhood, attributes she was certain would carry it through. But her belief in Boston was tinged with sadness. Now she understood a little bit about how New Yorkers who experienced 9/11 must feel.
"I mean, it happened — it finally happened," O'Kane said. "We were feeling sort of immune. Now we're just a part of everybody...The same expectations and fears."
In the hours after investigators released the photos of the men known only as Suspect No. 1 and Suspect No. 2, the city went on about the business of a Thursday night, a semblance of normality restored except for the area immediately surrounding the blast site. Restaurants that had closed in the nights just after the bombing reopened for business. At Howl at the Moon, a bar on High Street downtown, the dueling pianists took the stage at 6 p.m., almost as if nothing had changed.
But across the Charles River in Cambridge, Tamerlan Tsarnaev, 26, and his brother Dzhokhar, 19, were arming up.
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