Investigators in Boston will look for small clues

Thomas Frank, USA TODAY, April 16, 2013

Investigators in Boston will be crawling on sidewalks, scraping up fragments and analyzing them for clues that could lead to the person or group that planted two bombs near the Boston Marathon finish line Monday.

Those kind of remnants have helped the FBI solve other notorious bombings, including the 1993 attack on New York’s World Trade Center, where a fragment of the van that carried the explosives was found in the rubble and quickly led authorities to arrest one perpetrator.

“Investigators are meticulously searching the scene to uncover any piece of evidence from the explosive device,” said Art Gordon, a retired special agent with the Bureau of Alcohol Tobacco and Firearms. “You might find wires from a blasting cap or remnants of the explosives. All of these items are recoverable on the scene. It takes getting down on your hands and knees.”

FULL COVERAGE: Boston Marathon explosions

That’s literally what authorities did in 1988 to solve the bombing of Pan Am Flight 103 over Lockerbie, Scotland. Crawling over hundreds of acres of fields, they found a fragment the size of a thumbnail that was part of a circuit board used in the bomb and another fragment embedded in a piece of a shirt. That evidence led authorities to two Libyan operatives.

In Boston, investigators will attempt to trace remnants back to their point of sale or manufacture. They also will study what’s left of the bombs — their components and their structure — to find hallmarks of a known bombmaking group or individual.

“In some investigations, they can compare remnants with devices that they know about or have recovered” in other investigations, said Brian Michael Jenkins, a terrorism analyst at the RAND Corp. “Bombmakers have a signature — the way they cut wire, the explosives they use and the way they put bombs together.”

The signatures might point to terrorist groups based in a certain country, or a domestic group. It’s possible, however, that the bombs in Boston were made by someone with no known bombmaking history or terrorist affiliation, making the suspect harder to find.

“Most of the recent terrorist plots in the U.S. that have been uncovered involved a single individual who had carried out no previous act,” Jenkins said. “This can easily be done by a single individual with a relatively crude bomb. We may be looking for one person, and this person may not be formally connected with anything.”

Investigators have solved bombings using each of a bomb’s main components — the explosive itself, the wiring, the detonator, the power source, the container and any shrapnel, said Richard Roth, a homeland-security consultant and former Secret Service agent.

Investigators probing the bombing at the 1996 Summer Olympics in Atlanta received a big boost in early 1998 by tracing nails that had been used as shrapnel in a similar attack a year after the Olympics. The nails led them to Eric Rudolph, who was caught in 2003 and is now serving multiple life sentences in a maximum-security federal prison.

But Roth, noting that it took seven years to target and apprehend Rudolph, said, “We could be in for a long haul here.”

Investigators will have an enormous amount of video footage, from TV cameras broadcasting the marathon, spectators making their own recordings and security cameras in the area that may have images of a suspect or a vehicle. The bombing took place in Boston’s Copley Square, a heavily traveled area of shops, restaurants and offices.

“The biggest problem will be sorting through the wealth of information,” said Randall Larsen, founding director of the WMD Center, which researches weapons of mass destruction. He recalled that investigators in London were able to quickly arrest people responsible for the subway and bus bombings in 2005 by using that city’s unparalleled network of security cameras. “That’s why London has such an advantage over every other city,” Larsen said.

Gordon, the retired ATF agent, is optimistic that investigators will find helpful clues. “Although people think that just because a bomb goes off, everything gets blown up and is gone, it’s not. There’s a lot to be learned from processing the scene correctly,” he said.