One of Richard’s alleged killers, meanwhile, was on a different sort of errand.
Around 12:30 p.m. Tuesday, Dzhokhar Tsarnaev showed up at Junior Auto Body shop on Columbia Street in Somerville, a short walk from the Tsarnaevs’ home on Norfolk Street on the Cambridge-Somerville line. He was there to pick up a white Mercedes-Benz he had left there two weeks earlier, a car he had said belonged to a girlfriend.
The car’s rear bumper wasn’t fixed yet. But Dzhokhar told the mechanic, Gilberto Junior, he would take it anyway.
“I need it now,” Dzhokhar said.
Normally the 19-year-old was relaxed and happy, chatting about soccer, smoking weed, and girls. But on the day after the bombing, Junior said, Dzhokhar appeared anxious. He was biting his nails, and his knees shook so much that Junior thought the kid had been “popping pills.”
“I wish I knew,” Junior said later, looking at his hands.
By Tuesday afternoon, Dzhokhar was back on campus at UMass Dartmouth, according to UMass Police Chief Emil R. Fioravanti. Card swipe records, videotape, and interviews with students show the 19-year-old sophomore spent time on campus between Tuesday and Thursday, said the chief.
At 9:05 p.m. on Tuesday, the college sophomore used his swipe card to enter the Fitness Center, a small room packed with free weights, weight machines, running machines, and flat-screen TVs. Outside the fitness center, Dzhokhar showed up for 5 or 10 seconds on a security camera.
He also posted more Twitter messages Tuesday, including one about a photo of a bombing victim. Internet rumors swirled about the injured woman in the picture, claiming her boyfriend had planned to propose, but found her dead.
“Fake story,” Dzhokhar tweeted.
That night he also posted lyrics from a song by the rapper Eminem: “Nowadays everybody wanna talk like they got something to say but nothing comes out when they move their lips; just a bunch of gibberish.”
The suspect appeared to be resuming his normal life, unconcerned that he could be caught, working out at the gym instead of hiding or running.
“I’m a stress-free kind of guy,” he tweeted after midnight.
But back in Boston, investigators combing through hours of footage on Tuesday had begun to see a pattern among the various videos, their attention drawn especially to two young men walking east along Boylston Street in the 12 minutes before the explosions.
Neither seemed particularly worried about hiding their appearance — the man in the white hat even turned his cap around backward, giving the cameras a full shot of his profile. Suspect number 2, as he became known, talks nonchalantly on his cellphone, then scarcely reacts at all when the first bomb goes off.
When Alben, of the State Police, saw the results of the analysts’ work on Wednesday morning, he couldn’t believe it: they had captured an image of the young man in a white hat dropping a backpack outside the Forum restaurant and then walking away.
“There was a eureka moment . . . It was right there for you to see,” said the colonel. “It was quite clear to me we had a breakthrough in the case.”
Pinning down identities
They had faces. Now they needed names.
Even after authorities isolated the images of the two suspected bombers, they weren’t able to pinpoint the suspects’ identities — an essential puzzle piece that was still missing Wednesday.
The FBI has poured millions of dollars into facial recognition technology over the years so it can quickly cross-check an image against millions of other pictures in government databases.
In this case, both brothers were already in existing government databases, including the Massachusetts Registry of Motor Vehicles and federal immigration records. They were legal immigrants from the former Soviet republic of Kyrgyzstan, in theory allowing the FBI to find their names.
But it’s not clear which databases the FBI checked. And it may not have mattered. The pictures, taken from surveillance cameras above street level, were likely far too grainy when zoomed in on the brothers’ faces. And the older brother was wearing sunglasses, making their task even harder.
In addition, unlike in a traditional mug shot, the camera wasn’t looking at their faces head-on.
Investigators worked feverishly Wednesday trying to identify the men, searching other photos and video, trying to find high-definition images.
“We still needed more clarity,” said Alben, of the State Police. “As good as the videos were, we needed more clarity.”
They continued hunting down new images. David Sapers, owner of the Boylston Street candy store Sugar Heaven, said he had called the FBI hot line on Tuesday to inform authorities that he had video. Wednesday morning, Homeland Security officers showed up and spent more than three hours reviewing the footage frame by frame with the store’s manager, said Sapers. Continued...