Having more photographic evidence from a scene does not necessarily tamp down outlandish theories. Photo: Reuters
Minutes after the Boston bombing, Twitter, Facebook and YouTube began filling up with pictures and videos documenting the attack. There were clips showing the explosions, graphic images of the injured and chilling photos of the gruesome aftermath of the scene.
The images were captured by bystanders with mobile phones and digital cameras, by professional photographers working for news organisations and companies that sell souvenir pictures to runners, and even by the runners themselves. It's likely that the attackers were counting on this imagery: Marathons are public monuments to thousands of moments of personal triumph, the sort of moment that now commands us to pull out our phones and press record. Whoever they were and whatever their larger aims, the people who did this wanted us to witness it.
My Slate colleague Dave Weigel sees a small silver lining in these photos. Photographic evidence, he argues, will tamp down conspiracy theories about the attack. There are already some irrational people arguing that the government planned this attack as a kind of "false flag" operation, but unlike truthers who glommed on to previous catastrophes, Boston conspiracy theorists will have to confront photos and eyewitness accounts that contradict their theories about what happened.
There's also the hope that all the images will help investigators get to the bottom of what happened. Law enforcement officials have asked people to submit their marathon pictures and videos with information. By piecing together everyone's pictures, the theory goes, officials may solve this investigative puzzle.
I hope Weigel is right that pictures help us bury nut-job theories about what really happened in Boston. But I'm with my other Slate colleague Amanda Marcotte, who points out that conspiracy theorists are rarely dissuaded by evidence.
As I discovered in a book I wrote about how conspiracy theorists and other hucksters spread false stories online, truthers often begin with an inchoate belief – e.g., the government can't be trusted – and then selectively interpret evidence to support their claims. As a result, having more photographic evidence from a scene does not necessarily tamp down outlandish theories. In fact, sometimes just the opposite happens – the more pictures there are, the more places there are for truthers to find "overlooked evidence".
In that way, first-hand documentation often ends up feeding and bolstering conspiracy theories. People cling to their theories because they swear they've seen photographic proof.
We saw exactly this effect in 9/11. When the second plane hit the World Trade Centre, dozens of television cameras and tens of thousands of people, many armed with digital cameras, were glued to the buildings. The World Trade Centre attack was one of the best-documented catastrophes in history, and one of the few times that an act of murder has been captured on live television. (One of the only other times was when Jack Ruby killed Lee Harvey Oswald.)
Compared to the Kennedy assassination – which was documented by a single iconic film reel of terrible fidelity – there were so many pictures of what happened on 9/11 that it seemed unthinkable that anyone would question the official story in the same way people doubted that Oswald had killed Kennedy alone. But doubts about 9/11 began immediately, and pictures were a key part of the alternative storylines.
If you watch Loose Change, the touchstone 9/11 truther documentary, you'll see lots and lots of photos that purport to prove that the government was somehow involved in the attack. Yes, the pictures don't tell the full story – there were lots and lots of pictures taken on 9/11 that call the conspiracy theories into question – but that's not apparent in the film, which picks and chooses just the ones that support the conclusions it wants to make.
I suspect we'll see the same thing in Boston. Pictures of real life after an attack are messy – people and objects are often in places that don't seem to make sense, especially when examined by amateurs who don't understand the context in which the photos were taken.
By scrutinising enough shaky, blurry pictures and videos closely enough, sceptics are sure to spot little things that seem off. Look, there's a man on the roof of a building – why? Why is this garbage can here rather than there? Does the man in the gabardine suit look like a spy? After finding enough of these little things that don't make sense, the conspiracy-minded often paste them into a larger storyline that, to them, makes a whole lot of sense if only people would consider it.
None of this is to say that pictures aren't valuable. They are; trained investigators who spend hours scrutinising all the documentary evidence from the Boston bombings may well find clues pointing them to the culprits. But let's not expect anything more than that. Conspiracy theorists believe what they believe because they believe it. Pictures aren't going to stop them.
Farhad Manjoo is Slate's technology reporter and the author of True Enough: Learning to Live in a Post-Fact Society. Twitter: @fmanjoo