BY SPENCER ACKERMAN 04.18.13 3:45 PM
Lauren Crabbe went to Boston on business. She was there to do some research and a little networking for the coffeeshop she’s opening. She never expected that the photos she snapped might be evidence in a bombing investigation.
But when Crabbe, a freelance contributor to Wired’s Gadget Lab, heard the FBI wants spectators at Copley Square to provide any photos and videos of the scene, she remembered the photo she snapped with her iPhone 4S. It provides an expansive view of the Marathon’s finish line about 90 minutes before two bombs went off on Monday afternoon, killing three people and injuring more than 180.
The photo — click to enlarge — shows a lot of people, what they’re wearing and where they’re positioned within the crush of Marathon fans. It’s important to law enforcement, as it “can be of use in putting the mosaic together,” says Robert McFadden, a former Navy terrorism investigator. Crabbe’s wide-angle panoramic photo “could be one of the many critical pieces of the map of the investigation.”
The panorama photo was one of seven shots Crabbe snapped with her phone during a leisurely stroll and later handed over to investigators. (For those wondering, sometimes the software crafting the panorama effect distorts the limbs of people captured on camera. It’s not an alteration — though, given the subject matter, it’s certainly eerie.) They’re the sort of pictures you take as a spectator: Runners powering through the final leg of the race, cups of Gatorade at an aid station, random things that caught her eye.
“The things you just take photos of, your observations, ‘Oh, I can Instagram that later,’” she said. “You never think this could be a crime scene.”
Crabbe was in Boston for the Specialty Coffee Association of America coffee expo. She decided to check out the race — a Boston tradition for 117 years — at the encouragement of her Airbnb host. Enjoying the “half-race, half-party” atmosphere, she snapped the photo above around 1:30 p.m. Monday before heading to Logan International Airport for her 4 p.m. flight. She was at the airport when her phone started getting flooded with texts and calls from loved ones making sure she was OK. She had no idea what had happened, and how close she’d been to the bombs before they blew.
Once home, Crabbe read that investigators wanted any photos and video taken at Copley Square, so she sent a message with her contact information to the FBI’s anonymous tip line. Shortly before noon Wednesday, Yogesh Sharma from the FBI’s San Francisco counterterrorism task force emailed her to ask what she had. Crabbe sent him seven photos, and Sharma called to ask about two minutes’ worth of basic follow-up questions. Where she was standing? Did she see anything else she thought was suspicious? He even threw in a leading question, asking, “So, you took this photo two hours before the bomb went off?”
Crabbe replied, “‘I didn’t know when the bomb went off, but I took it at 1:30.”
Now comes the FBI analysis of those photos, using biometric tools like facial recognition. Reportedly, asurveillance camera above the Lord & Taylor building at Copley Square have provided investigators with images of two men they’d like to question.
The possible identification of a suspect does not mean all those photos collected by the FBI are useless. Pictures and video from people like Crabbe contain distinct vantage points and angles that help investigators cross-check people they might find suspicious or worth questioning.
“The old cop in me always wants to look hard at guys with shades and watch caps,” says Mike Marks, a recently retired Navy investigator, who, when viewing Crabbe’s photo immediately scanned it for men with a “squared away military look” carrying backpacks.
“There are advanced software and analytical hardware that helps measure, to minute detail, the physical features terrain of face and physique, such as distance, angle, complexion, etc.,” McFadden, another Navy Criminal Investigative Service veteran, said in an email.
Some of these tools are purchased off-the-shelf; others take advantage of “the latest advances developed by Darpa, et. al,” he wrote, declining to be more specific. The Defense Department is researching tools to can identify people, at a distance, by the way they walk, the shape of their face,and even the way they smell.
But some of the best tools investigators have for photo analysis are their naked eyes. Crabbe’s photo might be a static image, focused on people. But investigators examine details in the spaces in between people, things like their position relative to other spectators and their stance near natural egress routes. On their own, details simply provide orientation. Combined with details gleaned from other photos and layered over time, investigators can assemble an understanding of what normal behavior at the Marathon looks like — and perhaps what it doesn’t look like.
“There’s been a lot of research conducted and data put together in recent years (I’ve been a part of some projects) on what do, say, 99 out of 100 people do in such a situation as in Boston — both before and after the event,” McFadden writes in his email. “And then [you] look for the abnormal behavior (such as running in the opposite direction as almost everyone else). However, often it is just ‘not normal’ or inexplicable when the person is found and interviewed. But it is a definite priority lead, to track down the ones that just don’t fit the pattern and can produce significant case results.”
In other words, it’s unlikely that any single image will crack the case. Investigators’ advantage — the entire rationale for calling for spectator photos and videos — is to match them against a broader picture, over time, of what Copley Square looked like. It’s also what helps distinguish professional investigators from the well-intentioned amateur sleuthing that’s happening on 4Chan and Reddit; and the tabloid insanity of the New York Post.
Crabbe simply wants to help. She was reluctant to post her panoramic photo on social media — “I hate to think it was one of the last photos taken of the victims,” she says — but felt comfortable giving the images to professionals who know how to interpret it.
“Either this is a photo of suspects or this is a photo of victims,” Crabbe says. “And I tend to look at it as a photo of victims.”