“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.
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.
Authorities urged that anyone with images of the area call 800-CALL-FBI (800-225-5324).
“We are particularly interested in reviewing video footage captured by bystanders with cellphones or personal cameras near either of the blasts,” said Attorney General Eric H. Holder Jr. “In an investigation of this nature, no detail is too small.”
The danger in any such investigation is that officials will be so overwhelmed by raw data that important clues may be missed. Philip Mudd, a former senior official at the FBI and the CIA, said that “99.4 percent of what you have is chaff. The wheat will emerge, but it could take a few days unless you get a break.”
Federal investigators are scrubbing every fragment from the bombs for clues about where its components were obtained and by whom.
President Obama, who plans to travel to Boston on Thursday for an interfaith service dedicated to the bomb victims, called the attack “heinous and cowardly” and termed it “an act of terrorism.”
Police said they do not have any suspects. After a briefing by intelligence officials, Sen. Saxby Chambliss (R-Ga.) said, “There are a lot of things that are surrounding this that build an indication that it may have been a domestic terrorist.” But neither he nor law enforcement officials cited any specific evidence pointing to a source of the attack.
Chambliss said a Saudi national who was injured in the bombings is considered a witness. The man, who is recuperating at a Boston hospital, is in his 20s and is in the United States on a Saudi scholarship to study in the Boston area. An official at the Saudi Embassy in Washington said the man cooperated with police and gave authorities permission to search his apartment.