fb-pixelVisual evidence isn’t always as definitive as it feels - The Boston Globe Skip to main content
Evan Horowitz | Quick Study

Visual evidence isn’t always as definitive as it feels

Desperate to know if his wife is cheating on him, Shakespeare’s Othello demands one sort of evidence above all: Visual evidence, or what he calls “ocular proof.” If he were around today, he might ask for cellphone video, which has increasingly become a vital source for this kind of visual proof.

Grainy, cellphone footage of a police shooting in South Carolina last weekend has shown that — contrary to the officer’s original report — the victim was actually shot in the back while running away. Absent that footage, there might not have been a path to justice.

Video isn’t a cure-all, however. In other cases, like the strangling death of Eric Garner, public outrage and ocular proof haven’t led to charges.

Advertisement



And for the future, there’s a broader concern with visual evidence. It isn’t always as definitive as it feels. Just ask Othello, who’s led murderously astray by the evidence he sees. We happen to find ourselves in a unique technological moment, when the ability to capture video is ubiquitous, but the ability to doctor it remains fairly limited. That’s why cellphone footage can be so decisive, as in the South Carolina shooting.

However, someday soon video manipulation may be as familiar as “Photoshopping.” When that happens, the idea of justice via cellphone may become far more suspect, and that could have profound implications for both police and citizens.

What happened in South Carolina?

A white police officer named Michael Slager shot a black man named Walter Scott after a routine traffic stop in a town called North Charleston.

Initially, the officer said he fired on Scott because Scott grabbed his stun gun. A nearby bystander, however, captured the incident on his phone, and the results bore little resemblance to Slager’s telling. Scott was running away when he was shot multiple times in the back. The video also seems to show the officer picking up his stun gun and dropping it beside Scott’s fallen body.

Advertisement



Following the release of that video, the officer has been charged with murder and fired from the police department.

Did the video make the difference?

Cellphone footage seems to have completely transformed this case. Had the bystander kept his phone in his pocket, and been forced instead to merely tell his story to police, it would be his word against the officer, a very different balance.

His video has an objective force that no eyewitness account can match. And this feeling — that the video reflects a kind of objective truth — persists even as the footage gets passed around. Wherever you encounter it on the Internet, the video feels like a window onto the real events of that day in South Carolina.

So, is more video the answer?

Unfortunately, video footage has proved less decisive in a number of other controversial cases.

Last December, a video surfaced of police in Staten Island using a choke hold against a man selling loose cigarettes. That man, Eric Garner, died during the altercation, but police were not charged in his death, in spite of the footage.

Having said that, the Garner video did bring together protesters from cities across the country, helping to galvanize a broader movement.

Are there any risks that come with these video?

Tempting as it may be to assume that video footage gives us a privileged look at what really happened, this isn’t always the case.

Video can be doctored, whether through the editing process or through more elaborate visual effects. And while readers and media outlets have gradually learned to become more attentive to changes in photographs, the same isn’t yet true of video.

Advertisement



There’s no reason to think that the pivotal video of the South Carolina shooting was doctored in any way. But as video manipulation becomes ever easier, there’s a risk that footage could be altered to distort the truth, rather than reveal it.

Just to give a sense for how powerful — and dangerous — doctored video can be, consider this experiment from two British academics. To begin with, they asked people to play a simple gambling game with fake money on a computer. Unbeknownst to their subjects, researchers put together video footage altered to make it seem as if the subjects had, in fact, cheated. And in spite of the fact that no one had actually cheated, many of the people who saw the video came to believe that they did cheat — signing confessions and openly admitting their guilt.

Can we guard against video manipulation?

Police body cameras might actually be a way to hedge against the risk of doctored video in the future.

The mayor of North Charleston has already announced that his patrol officers will start wearing body cameras. And all across the country, communities and police departments have been wrestling with questions about the costs and benefits of such cameras, including whether they would protect citizens against police abuses, whether they could protect police against wrongful complaints, if it’s possible to deploy them in a responsible and cost-effective way, and if they amount to a violation of people’s right to privacy.

Advertisement



If body cameras became more common, they could serve as a trusted, legally protected source of unedited video, with the recording as carefully guarded as other kinds of evidence. That way, even if someone did try to plant misleading footage, the police videos could provide an authoritative check.


Evan Horowitz digs through data to find information that illuminates the policy issues facing Massachusetts and the United States. He can be reached at evan.horowitz@globe.com. Follow him on Twitter @GlobeHorowitz