Joint taskforce involving FBI, CIA and National Security Agency sifting through debris at crime scene in hunt for those responsible
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An joint taskforce led by the FBI was sifting through bomb debris and viewing thousands of photographs on Tuesday in the hunt to establish whether a foreign or homegrown terrorist was responsible for the Boston Marathon bombs.
Boston's police commissioner, Ed Davis, described the finish line of the marathon as "the most complex crime scene that we've dealt with in the history of our department".
Led by the FBI's Boston office, the joint taskforce was searching for wire, shrapnel and ball bearings, and any explosive residue in the hope of reconstructing the bomb and identifying the terrorist's "signature".
The taskforce was working alongside the CIA and the National Security Agency, which monitors phone calls and other communications worldwide, to establish whether there was any international "chatter" before or after the bombings.
"We will go to the ends of the earth to find subject or subjects responsible for this despicable crime," the FBI special agent in charge, Richard DesLauriers, told a press conference in Boston.
However, the FBI has repeatedly briefed in private over the last decade that it regards the main threat as coming not from al-Qaida or one of its affiliates. Instead, it fears attacks from domestic terrorists, whether someone angry over taxes, white supremacists, survivalist militia groups, or disgruntled Muslim Americans attracted to al-Qaida.
Don Borelli, the former assistant special agent in charge of the New York Joint Terrorism Task Force, the biggest and most active in the FBI, investigated terrorism cases that included the 1995 Oklahoma City bombing, the 1998 east Africa embassy bombings, the attack on the USS Cole in the Yemen, and the 2009 al-Qaida plot to bomb the New York subway system.
Borelli, who retired from the FBI in 2010 and is now with the Soufan international security group, said when there is a terrorist incident, there is a checklist of things to be done. "We have a crime scene that has to be processed because a crime scene is perishable. We are sifting through parts that could hopefully help investigators reconstruct the bomb.
"They will try to establish the exact place where the bomb was detonated. They will look to see if it created a crater. They will look at flash marks and the size of the flame and will try to figure out how far from that ground zero point are they finding remnants.
"Not all the explosive will go off. There will be residue. Was it black powder? How was it detonated? Was it on a timer, a wristwatch, or by a cell phone or old-school – a slow-burning piece of cord? I would think it was more sophisticated than that, as it would have produced smoke."
The analysts will hope there is a significant piece of the bomb intact that could provide a fingerprint or a swab for DNA.
The taskforce said there was no specific suspect in the Boston attack and no idea of the motive, and no surveillance videos had yet shown the bombs being placed. Officials have urged members of the public to hand over mobile phone footage of the bombings.
Borelli said investigators would regard it as vital to carry out swiftly as many witness interviews as possible. "The more days that go by, people's memories fade, and they see television and become confused about whether it was something they saw or something they saw on television," Borelli said.
"Video footage is a big part of the investigation. FBI agents will have handfuls of informants too that they will reach out to."
The FBI office in Boston would take the lead in the Joint Terrorist Task Force, which includes other major police and federal agencies, Borelli said, with analysts and other technical staff drafted in from Washington. There would also be support staff. "This office would normally work 8.15am to 5pm, and now they are [working] 24 hours. People have to go on shifts and take rests," Borelli said.
At the White House, officials would be in constant contact with the FBI, looking to gather as much information as possible. Juan Zarate, the deputy national security adviser for combating terrorism from 2005 to 2009, said: "There would be a giant sucking sound within the White House trying to get as much information as possible from the FBI, as well as intelligence pre- and post- to see if there were any clues. It is not just about forensics."
The White House would immediately be concerned about the possibility of subsequent attacks, Zarate said. "When I was in office, the question was: 'What next?' That explains why there was increased security around the country. If there is not a lone wolf, there may be others, prepared to do this again."
Zarate said the bombing was a nightmare scenario for police and security, chasing a potential lone wolf who hit a soft target. "We live in an open society. We do not want to go into lockdown. It is hard to secure against."
Borelli was optimistic there will eventually be an arrest. "The FBI has a lot of experience in this, from small-scale bombs to ones that bring down buildings," he said. "I have no doubt they will figure out who is responsible."