The Boston Globe said authorities are reviewing an image of a potential suspect “carrying, and perhaps dropping, a black bag” at the bombing scene. A photo circulated on the Internet site Reddit appeared to show a man wearing a backpack at the site and then walking away without it.
Those reports have not been independently confirmed, and the FBI and Boston police said no arrests have been made, despite other media reports that said a suspect was in custody. And some previous investigations of terrorist incidents yielded suspects who turned out not to be involved.
Massachusetts Gov. Deval L. Patrick (D), speaking on CNN, cautioned that while the investigation is “making some progress,’’ it is likely to unfold slowly. “It’s going to be methodical…this is going to take some time, a lot of time,’’ said Patrick, who has been briefed by investigators and asked the public for “patience.’’
If authorities do indeed have a suspect, it would be a major development in the massive probe of the bombings, in which explosive devices crafted from pressure cookers and stuffed with nails and ball bearings killed three people and injured at least 176.
With no one claiming responsibility for Monday’s attack, hundreds of investigators in Boston and Washington are combing through more than 2,000 video and still images of the race route, searching for clues that might help determine whether the bombings were an act of domestic or foreign terrorism, planned by an organized enemy or a lone actor.
“The range of suspects and motives remains wide open,” FBI Special Agent in Charge Richard DesLauriers said at an evening news conference in Boston. He said that the investigation is “in its infancy” and that evidence — including fragments of BBs and nails, as well as pieces of black nylon that could have been part of an “unusually heavy” backpack or bag holding the bombs — has been sent to the FBI lab at Quantico, where technicians will try to reconstruct the devices. He said it is not known how many people set off the bombs.
“It’s our intention to go through every frame of every video,” Boston Police Commissioner Ed Davis said.
(See the latest updates on the Boston Marathon bombings here.)
In the first successful U.S. terrorist attack of the smartphone era, that means authorities face the daunting task of looking at thousands of images from phones, business- and government-owned surveillance cameras, and even runners’ head cameras.