A new exhibition reveals how photography has been used to investigate acts of violence, including Stalinist purges and 21st-Century drone strikes. Fiona Macdonald finds out more.

“If the military chose to, they could zoom in and read what you’re writing now,” says Diane Dufour as I scribble in my notebook. The curator of a new exhibition on photographic evidence is explaining the precision of satellite images. Yet, she says, what the rest of us see is much blurrier.

Just opened at the Photographers’ Gallery in London, the exhibition Burden of Proof explores how forensic experts have used photographs and video to investigate crimes and acts of violence. One project is particularly chilling, making visible a form of warfare that often remains hidden. In March 2012, the aftermath of a drone strike in a Pakistani frontier region was filmed for just 22 seconds. The footage was smuggled out of Miranshah to Islamabad, and was broadcast on MSNBC in June that year.

The video – rare in documenting a site destroyed by a drone strike – offers more than just images of rubble. What appears in the clip as a hole in the roof, possibly made by a missile, is too small to be seen on publically available satellite imagery. “When satellite images are used for military purposes, they are incredibly precise,” Dufour tells me. “But when they are released to Google Earth and used for civilian purposes, they are degraded. A pixel represents half a metre by half a metre of ground. So that hole in the roof is nothing more than a darkened pixel.”

That hole in the roof is nothing more than a darkened pixel

The blurring of images is, says Dufour, to protect privacy and to preserve military secrets. (In 2014 the resolution was increased to about 30cm per pixel after lobbying from satellite companies). “This resolution was chosen because it is roughly the size of the human body seen from above,” writes Eyal Weizman, director of the agency Forensic Architecture, in the exhibition catalogue. “Not only do important details of strategic sites get camouflaged… so are the consequences of violence.”

Eye in the sky

“Drone strikes are executed at a significantly higher resolution than that of satellite photographs of the kind the NGOs or the UN use to monitor attacks,” writes Weizman. “This inverts one of the foundational principles of forensics since the 19th Century, namely that to resolve a crime the police should be able to see more, using better optics, than the perpetrator of the crime.”

Burden of Proof reveals the techniques that investigators have used to see crime scenes more clearly since the early 20th Century. “From the moment the first daguerreotypes were made, photography entered the courtroom,” says Dufour. “Those early judges, evaluating it as evidence, were asking the same questions that are being asked now.”

The exhibition ranges from photos of crime scenes taken in 1903 to the video of drone strike damage more than a century later. Some of the images are shocking – showing the corpses of murder victims from what has been labelled a “divine point of view”, a technique developed by Alphonse Bertillon – while others, on the surface, are more banal. Swiss forensic expert Rodolphe Reiss took close-up photographs of objects from crime scenes, breaking each down into its components. What appears to be a series of snapshots showing domestic items becomes more disturbing when considered in context. There is a dusty wine bottle, scratches on a bedpost, a crumpled handkerchief: Reiss’s accompanying text reads “Handkerchief used to strangle Madame Ducret, Beaumaroche, 24 September 1907”.

Long exposure

A keen photographer, Reiss applied his knowledge of cameras to the recording of fingerprints, footprints and traces of blood. He discovered that clues imperceptible to the naked eye – such as bloodstains on a washed handkerchief – could appear during the printing process. Reiss called it “the photography of the invisible”. Aiming to create “a permanent reconstruction of the scene” long after it had been cleaned up, he believed his images could reveal details overlooked during the investigation. He described photography as “humanity’s artificial memory”.

Photography can expose crimes years after they occurred

Photography’s ability to expose crimes years after they occurred is a theme in Burden of Proof. Polish photographer Tomasz Kizny has collected mug shots of prisoners executed under Stalin between 1937 and 1938, during what has become known as ‘the Great Terror’. They appear in the exhibition as a slide show, the faces of students, factory workers and nurses – some frowning, some defiant, some half-smiling. Many of the photographs were taken on the day of execution.

“The images were made to help the identification of prisoners,” says Dufour. “They were kept secret, but individual files have been released upon official request from the victim’s family – little by little, over decades. The pictures were a tool to commit the killings, but over time they have become evidence of a crime that was supposed to be hidden.”

One of the exhibits at Burden of Proof shows perpetrators directly confronting their crimes. At the Nuremberg hearing on 29 November 1945, 21 Nazi war criminals watched a film projected onto a screen in the centre of a courtroom. In the footage – labelled ‘Nazi Concentration Camps’ – Hollywood director John Ford and a team of cameramen documented what Allied forces found at Dachau under a strict set of protocols aimed at proving their veracity.

Göring, ‘viceroy’ of the Third Reich, clenched his vivid jaw.

Joseph Kessel, correspondent for France Soir, described the reactions of the accused as they saw the images projected in front of them. “Throughout the whole dark room, only two stretches of light were visible,” he wrote in a report. “On one of them, we could see the emaciated horror of the concentration camp. On the other, loomed the figures, laid bare, of the men who were responsible… Göring, ‘viceroy’ of the Third Reich, clenched his vivid jaws to the break. Field Marshal Keitel, whose armies had picked so many men doomed to mass graves, covered his eyes with a trembling hand… Frank, who had decimated Poland, collapsed into tears.”

Nazi war criminal Josef Mengele escaped before the Nuremberg trials: but his skull became the subject of another kind of forensic process. In what has been called a ‘trial of the bones’, investigators were asked to identify a skeleton found in a suburb of Sao Paulo in 1985. By analysing the bones, they believed it to belong to the Auschwitz doctor – but, as Dufour says, “they were missing an image to convince everybody”. German pathologist and photographer Richard Helmer superimposed a video image of the skull onto a photo of Mengele, proving it was him and creating an eerie image of the man at once alive and dead. “It was the beginning of the era of the ‘object’, as experts relied more and more on materiality – DNA, bones – and less on the witness to solve a crime,” says Dufour.

Pictures are mute in a way. Even if they say a lot they might be misleading.

Some images contain few clues without the knowledge of an investigator. “Pictures are mute in a way. Even if they say a lot they might be misleading, they might be hiding things,” says Dufour. “The role of the expert is to see that an image is interpreted in the right way.”

So, for the footage of the drone damage, she says: “If we look at the film we see only ruins – we can’t work out what happened. And then forensic experts take each frame of the 22-second film and analyse it in a way that will provide evidence of how, why and when the attack took place.” Weizman’s agency Forensic Architecture reconstructed the scene in a 3D digital model, cross-referencing data with satellite imagery and animating the shadows of the structure.

The image of a room in the Miranshah clip, peppered with red dots, becomes more than a scientific record through forensic interpretation. Its dotted white lines recall ashen imprints created by human bodies after the volcanic eruption at Pompeii. “The wall was scattered with hundreds of small traces from the explosion. There were two distinctly shaped gaps within the pattern of the shrapnel. The bodies of people in the room could have absorbed these fragments,” says Weizman.

“If so, the gaps are the outlines of the people killed and their bodies got captured by the wall, which functioned like photographic film. The people were exposed in the blast in a similar way to which a negative was exposed to light.”

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