For two years, between 2011 and 2013, the former Syrian military photographer known only as Caesar used a police computer in Damascus to copy thousands of photographs of detainees who were tortured to death in Bashar al-Assad’s jails. The media have run numerous stories about the man who managed to smuggle astonishing evidence of crimes against humanity out of the country – at great risk to himself and his family – but he had never been interviewed.

Month after month, for two years, this man, who has remained anonymous, took photographs of tortured, starved and burnt bodies. His orders were to photograph the bodies in order to document prisoners’ deaths. He then secretly made copies and transferred them on to USB keys so that he could smuggle them out of his office, hidden in his shoes or his belt, and pass them to a friend who could get them out of the country.

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The terrorists of Islamic State proclaim their atrocities on social networks; the Syrian state hides its misdeeds in the silence of its dungeons. Before Caesar, no insider had supplied evidence of the existence of the Syrian death machine. And these photos and documents were damning.

I had to find Caesar. The spectacular advances made by Isis, and the growing number of terrorist attacks by its followers, were drowning out revelations about the Syrian regime’s atrocities. The conflict had already left more than 220,000 dead. Half of all civilians had been forced out of their homes, others had been shelled, their towns and villages besieged by Assad’s army. Caesar’s pictures could put Damascus’s abuses centre stage again. He had to be found. Journalists from all over the world were already looking for him. I knew it would be hard – and it was. Twice I almost gave up. But I kept going, because it was imperative that this man should talk. His testimony was essential if we were to understand the horror at the heart of the regime.

The group that was protecting Caesar – members of the Syrian National Movement, a moderate Islamist opposition party – understood that my account of our meetings would not be a media scoop, but a descent into the unspeakable. It would give a voice to Syrians and make an impact for generations to come. After some months of negotiation, I was allowed to meet Sami, who had been Caesar’s closest collaborator, the friend who had supported him over the two years of this project. Sami and I spoke over Skype, four times, for hours at a stretch. After six months, Caesar agreed to talk.

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The first meeting was tense: they were on the defensive, I was fearful of “losing” them if I asked the wrong questions – if I demanded too many details, too soon. But in the end, Caesar spoke to me, on the record, several times. We talked for more than 40 hours. The result is an attempt to tell the truth. But it’s just a start. This is his story.

* * *

I am Caesar. I used to work for the Syrian regime, as a photographer with the military police in Damascus. I am going to tell you about my work before the uprising and during its first two years, but I can’t reveal everything because I am afraid the regime might recognise me through the details. I am a refugee in Europe. I’m afraid they will find me and eliminate me, or take revenge on my family.

Before the war, it was my job to photograph crime and accident scenes involving military personnel. Suicides, for example, or drownings; traffic accidents or house fires. Whenever there was an emergency call, the other photographers and I had to turn out and photograph the locations and the victims. Photograph this person, the investigator would tell us when we arrived at the scene, or that object. Our job complemented theirs. For instance, if there had been a shooting in an office, we’d photograph the spot where the body had been found, then we’d go and photograph it at the morgue, to show where the bullet had entered and exited the body. We might also photograph evidence such as a gun or a knife. If there had been a road accident, we’d photograph the place and the car. Then we’d go back to the office and a report would be written up, using our pictures. It would then be sent to the military courts so that the judicial process could begin.

At the time, the service was popular among the lower ranks. A lot of them wanted to join us because it wasn’t very hard work. We’d do a job every two or three days, and we could choose whether or not to wear uniform. The officers were less keen. There was no prestige in being in charge of photographers and archivists, and the military police didn’t have much authority – nothing like the intelligence services. What’s more, we didn’t have any dealings with civilians, so there was no possibility of making money from bribes, unlike customs, for example, or one of the government ministries. And we had no influence over the security services or the army.

Before the uprising, the regime tortured prisoners to get information; now they were torturing to kill

In the hierarchy, no one paid any attention to our work – our unit didn’t count. It was just one among dozens. The military police has dozens of departments. In Damascus alone, there are at least 30: photographers, drivers, mechanics, sports, the brigade that transports prisoners between the various levels of military intelligence, and so on. But the most important, of course, are in charge of investigations and prisons.

One day, a colleague told me that we were going to photograph some civilians’ bodies. He had just photographed the corpses of demonstrators in Daraa province [where the first big peaceful demonstrations took place]; this was in the first weeks of the civil war, in March or April 2011. He was crying as he told me: “The soldiers abused the bodies. They trampled them with their boots and shouted: ‘Son of a bitch!’”

He didn’t want to go back – he was afraid. When I was summoned to take the pictures, I could see what had upset him. The officers said the dead people were terrorists – but they weren’t, they were just demonstrators. The bodies were being stored at the morgue at Tishreen military hospital, not far from military police headquarters.

In the beginning, they put a name on each corpse, but after a while – a few weeks or a month – it was just numbers. At the morgue, a soldier would get the bodies out of the refrigerated drawers, lay them on the tiled floor so we could photograph them, then put them back again. Every time they called us for a photo session, a pathologist would be there before us. Like us, they didn’t have to wear uniform, but they were officers. For the first few months they were low-ranking, but then they were replaced by higher grades.

When they arrived at the hospital, the bodies were marked with two numbers, written on sticky tape, or in felt tip directly on the forehead or the chest. The tape was poor quality and often peeled off. The first number was that of the detainee himself, the second that of the branch of the intelligence services where he had been imprisoned. The pathologist, who had arrived earlier in the morning, would give him a third number, for his medical report. This was the most important number for our files. The two others might be badly written, illegible or simply wrong. Mistakes were sometimes made. The pathologist would write the medical number on a piece of card. He, or someone from the security services, would place it next to the corpse or hold it in his hand while we took the photo. Those are the hands that you see in the photos that I smuggled out. Sometimes you even see the pathologist’s or security agent’s feet next to the corpse.

Facebook Twitter Pinterest A man reacts as he looks at some of Caesar’s photographs, at the UN in New York. Photograph: Lucas Jackson/Reuters

The pathologists were our superiors. We weren’t allowed to talk to them, let alone ask questions. When one of them gave us an order, we obeyed. They’d say: “Photograph these bodies, from No 1 to No 30” – for example – “then push off.” To make identification easier for anyone searching the files, we had to take several shots of each corpse – one of the face, one of the whole body, one from the side, one of the chest, one of the legs. The bodies were grouped by branch – for example, there was one place for Branch 215 of military intelligence and another for the aerial intelligence branch. That made it easier to take the photographs and file them afterwards.

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I had never seen anything like it. Before the uprising, the regime tortured prisoners to get information; now they were torturing to kill. I saw marks left by burning candles, and once the round mark of a stove – the sort you use to heat tea – that had burned someone’s face and hair. Some people had deep cuts, some had their eyes gouged out, their teeth broken, you could see traces of lashes with those cables you use to start cars. There were wounds full of pus, as if they’d been left untreated for a long time and had got infected. Sometimes the bodies were covered with blood that looked fresh. It was clear they had died very recently.

I had to take breaks to stop myself from crying. I’d go and wash my face. I wasn’t doing well at home either. I’d changed. I’m naturally pretty calm, but now I would get annoyed easily – with my parents, my brothers and my sisters. Really, I was terrified. The things I had seen during the day kept coming back to me. I imagined my brother and sisters becoming these bodies. It was making me ill.

I couldn’t stand it any more, and I decided to talk to my friend Sami.

* * *

Caesar wanted to quit his job, he wanted to defect. Sami, a construction engineer, was a long-time family friend. The two men had known each other for over 20 years, but under the regime, there were things no one talked about: no one criticised the system, not even to close family or friends. Then Sami’s friend confided in him: “I’ve seen bodies showing signs of torture. None of them has died of natural causes. And there are more of them every day.” In tears, Caesar said: “What do I do?”

Sami was painfully aware of all the violent deaths that had gone unreported in Syria over the years. The prisoners who had died in silence, in the regime’s dungeons; protesters who had been killed and their bodies disappeared. He persuaded Caesar to carry on in the job, since he was in a unique position to collect proof from inside the system. He promised to support him, whatever happened. For two years, the young photographer risked his life copying the thousands of photographs of detainees that we can now see on the internet and in the Holocaust museum in Washington DC.

Before the civil war, there had been torture in Syrian prisons. Prisoners talked about it after their release. The regime intended these accounts to be told and retold; they wanted them to serve as a warning, so that terror would seep into every household. But Caesar’s photos report torture and death, indexed and archived by the regime. This time, it’s the state itself giving an account of the terror it has inflicted on its people. These pictures, taken in the dungeons of military hospitals, are irrefutable proof of brutality. Compared to the emotional amateur films made by freedom fighters in city streets, these official documents freeze the blood.

* * *

At one point they started sending bodies to Mezzeh military hospital, which is much bigger than Tishreen. Its official name is Hospital 601. While Tishreen was a five-minute drive from our office, it took half an hour to get to Mezzeh. It was easier to photograph the bodies at Tishreen because they were sheltered from the sunlight, in the morgue or, when that was full up, in the corridors. At Mezzeh, they were dumped outdoors, on the ground, in one of the garages where the cars were serviced. The hospital is at the foot of the hill where the presidential guard is based. You can see the hill in some of the photos, in fact, with the hospital watchman’s hut and the trees that mark the edge of its grounds. The presidential palace is just behind and above it. As well as photographing the bodies, my colleagues and I had to create files for them. We had to print the photos, sort them by category, stick them on cards and file them. It was methodical work – one person printed the photos, another stuck or stapled them, a third wrote the reports. Our superiors signed them and we sent them to the military courts. Before the uprising, we were dealing with soldiers’ bodies. Afterwards, we continued the same work, on civilian corpses.

The bodies rotted. Once, we saw a bird peck at a corpse’s eye

The numbers increased, especially after 2012. The work was non-stop. The officer in charge of our service would yell at us: “Why isn’t the work finished? The bodies are piling up! Come on, hurry up!” He thought we were dawdling, but we couldn’t work any faster. There were always more corpses, and defections in our unit meant that there were fewer of us left. The garage at Mezzeh started filling up with bodies that we hadn’t had time to photograph. There, in the sunshine and heat, the bodies didn’t keep well, especially when they’d been lying around for a few days. Even the soldiers didn’t want to touch them – they’d move them with the toes of their boots, they had no respect. The bodies rotted. Once, we saw a bird peck at a corpse’s eye. Other times, insects attacked their skin. And the smell ... we couldn’t get rid of it, it drove us mad. We had to find a way to deal with it, and then it became part of daily life.

We worked from 8am to 2pm, then we had a break until 6pm or 7pm, before going back to the office until 10pm. The days were long because we didn’t want to leave anything unfinished. We knew there would be more bodies to photograph the next day.

Several times a week, I took the photos to Sami. When I was alone in the office, I’d copy them on to a USB stick that he had given me, always afraid that someone would come in and see me. When I left, I’d hide the stick in my heel or my belt. On my way home, I’d have to pass four or five army roadblocks. I was terrified. I didn’t know what could happen to me. The soldiers might want to search me, even if I had my army ID.

* * *

Just like the communist-era eastern bloc, Syria records and files every bit of information, every document. The state suspects everyone and tries to prevent any deviation from the rules. He who obeys orders must show he has obeyed them. He must convince his superiors of his compliance for fear of being classed as insubordinate, cowardly or worse – and ending up in jail without trial. So, prisoners die of hunger or torture in the intelligence service detention centres? It’s a secret, of course, but the event is duly recorded and rubber-stamped, alongside a death certificate attributing the prisoner’s demise to natural causes.

At the foot of the presidential palace, corpses arrived almost every day, to be dragged, carried and sorted according to the branch of the intelligence services where they had been detained. Every day, the pathologist arrived at about 7am. Holding his notebook, a block of big sheets of paper stapled together and divided into three columns, he went from one body to the next. The photographer took his shot with a Nikon Coolpix P50 or Fuji digital camera, then the pathologist returned to his notebook to record the three numbers in the relevant columns.

A soldier, the “witness”, accompanied him and told him what characteristics to note down in the first column: approximate age, height, skin and hair colour, presence of tattoos or bullet holes ... and the cause of death, invariably “heart attack” or “respiratory problems”. Naturally, there was no mention of torture.

The pathologist then drew a line under the information and moved on to the next person. On average, each page held the details of three or four dead people. The medical report was archived in the pathologists’ offices in Tishreen hospital.

After finishing their photos, Caesar and his colleagues returned to base to draw up their own report for the military courts. Before the war, at the start of the uprising, each dead person had his or her own file card. Gradually, as the bodies became more and more numerous, one card had to hold the details of 10, then 15, then 20 detainees.

When Bashar al-Assad’s father, Hafez, ruled Syria, more than 17,000 detainees disappeared in the late 1970s and the early 80s. The Syrian Network for Human Rights (SNHR) estimates that more than 215,000 people have been detained since the start of the civil war, and that in almost half of the cases, none of their relatives have the slightest information about them. By December 2014, the SNHR had succeeded in drawing up a list of 110,000 names.

* * *

Seeing these photos on a computer screen was even more painful than photographing the bodies. Out there, with corpses all around us, we couldn’t hang around. The pathologist was hurrying us along, and agents from the security services were watching us and noting our reactions. In Syria, everyone watches everyone. And as we weren’t allowed to ask questions, it was easier to take our photos without really looking at the injuries; it was simpler to try to feel nothing.

Facebook Twitter Pinterest Caesar (disguised in a hooded blue jacket) listens to his interpreter before he speaks to the US House Committee on Foreign Affairs in Washington DC. Photograph: Jonathan Ernst/Reuters

Back at our office, however, we had time – no one was harrying us. And there, as we printed the photos and stuck them down, we couldn’t avert our eyes. It was terrible. The scene was right there: the detainee came back to life in front of us. We saw the body clearly, we imagined the torture, we felt the blows. Then we had to write the report – as if to fix what we had seen a little more firmly in our memories. In one month in the cells, a prisoner’s face might have changed completely – so much that we could no longer recognise them.

One of my friends died in detention. We photographed his body without knowing who he was. Only much later, as I was discreetly looking for information on behalf of his father, did I realise that his photo had passed through our hands and I hadn’t recognised him. He had only spent two months in prison. And this was someone who I used to see almost every day before he was locked up.

It was the military police who told his father that his son had died in detention. He didn’t want to believe it. I had to tell him it was true: “I contacted the military hospital and they confirmed that your son was dead.” In fact, I’d searched our archives and found the photo. I wasn’t allowed to tell him that, of course. No one knew that each detainee’s corpse was photographed as a matter of course before being thrown into a mass grave.

One day, one of my colleagues was at Mezzeh hospital. Bodies were lying side by side. As he stood over one of them, he got the impression that he was still alive. He was breathing quietly. “Should I photograph him? He’s still alive,” my colleague asked the soldiers responsible for transporting the bodies.

The pathologist arrived and was furious. “What do you mean, he’s still alive? What am I supposed to do? That’s going to change all my numbers!” He was angry because he had already filled his notebook with the corpses’ medical numbers. If this man was still alive, he’d have to cross some out, allocate new ones, redo the entries, the lot. “Don’t worry,” a soldier told him. “Go and have a cup of tea and it’ll all be sorted out by the time you come back.” When he returned, they finished taking the photos.

At the beginning, we were disgusted. Repelled. I’d hardly eat anything for three or four days. Then it became our daily routine, a part of us. We bottled it up. It was the only way we could keep going. What else could we do? If we gave vent to our feelings, we might be arrested and tortured to death and join those bodies. We were also afraid for our friends and families.

What else could we do? If we gave vent to our feelings, we might be arrested and tortured to death and join those bodies

There were about a dozen photographers in my team. We supported each other, but we couldn’t really confide in each other. Sometimes, a couple of us would have a whispered conversation, not daring to shut the office door in case someone imagined that we were plotting and criticising the regime. Anyway, we weren’t allowed to shut the door. We’d say, “On Judgment Day, we’ll have to account for our actions: ‘What did you do during all these years with this criminal regime? Why did you stay?’” And we were afraid. What could we possibly reply?

For those two years, I was caught in the crossfire. I was afraid of being arrested by the rebels because I worked for the regime, and of being caught by the regime because I was collecting this evidence of torture. My life was in danger from both sides – and my family was in danger, too.

* * *

Sami regularly supplied Caesar with USB sticks – at first with a capacity of 4GB or 8GB, then 16GB. Sometimes, Caesar worried that he might have missed some photos, so he recopied the whole month’s images on to a CD, with the increased risk of discovery. Sami would then copy everything twice – first, on to his home computer’s hard disk, with generic file names in case one of the regime’s agents stumbled across them, then on to an external hard drive. The process took agonisingly long minutes, but it was essential: only the original photos would have the metadata (date, type of camera, etc) that would prove when they were taken, and the high definition that would make it possible to analyse injuries and produce a probable cause of death. To make sure that nothing got lost, the photos were immediately sent abroad via the internet – in lower definition this time, to speed up the transfer time. With power cuts and unreliable phone lines, communication could be hit and miss.

When the regime attacked his town, Sami took his wife and children somewhere safer. Then he came back to find one of his friends, who had been helping him out on the photo transfers since the beginning. They took Sami’s computer and external hard drive, put them in a bag and hid them under a pile of rubbish. It was too risky to take them past an army roadblock. As the mortar shells began to fall more heavily and the first soldiers moved on to the streets, the two friends hid in a nearby house. Hauling themselves up into the cavity above a false ceiling, they hid for three anxious days and nights. Sami thought about his family, about his father, about the rabbits he was raising on the roof of their home. Through a crack in the wood, he tried to observe what was going on. One day, he remembers, “We saw soldiers force a young man to say, ‘There is no God but Bashar,’ then one of them killed him. “We were not afraid of dying, but we were afraid of dying like that.”

* * *

We wanted to get these photos out so that the dead people’s families would know that their loved ones had passed away. People had to know what was going on in the prisons and detention centres. When Bashar al-Assad falls, you can be sure that the regime will want to destroy the evidence.

Why does the regime keep these photos? I have often wondered. Why note down these detailed descriptions of the bodies and keep the photos on file? I’m a simple man, not a politician, and I’m going to give you a simple answer. The intelligence and security services don’t collaborate. They don’t know what the others are doing. Each one is responsible for its own organisation and works to serve its own interests. For 50 years, the military police have recorded the details of accidental deaths involving the military, in case it’s needed for the military courts. The regime documents everything so that it will forget nothing. Therefore, it documents these deaths. The photos are useful for judges and investigators. They complete their dossiers. If one day the judges have to reopen cases, they’ll need them. After the start of the revolution and during the war, we simply kept to the same routine. And the regime never imagined that one day our work might be used against it.

The security services feel invulnerable. They can’t imagine that one day they will be called to account for their abuses. They know that great powers support the regime. And they never thought that these photos would get out and be seen by the wider world.

Facebook Twitter Pinterest ‘We thought our work would mobilise public opinion. But the politicians want to turn the page and negotiate with Bashar al-Assad.’ Photograph: Lucas Jackson/Reuters

In fact, I wonder if the security service bosses aren’t more stupid than we think. Busy repressing demonstrators, looting the population, killing, they’ve forgotten that their abuses were being documented. Look at the chemical attack on Ghouta! Those responsible knew there would be evidence of what they had done – yet they still fired their rockets.

During the two years when I was secretly copying these documents, I was afraid for my family and for my own safety. I had started down this road and there was no going back. I knew that one day I would stop this work, but I didn’t know when. I kept putting the moment off. But eventually I realised, I had to leave.

* * *

In January 2015, in a long interview with the American magazine Foreign Affairs, the Syrian president, Bashar al-Assad, repeated his criticisms of the photographs. At one point, the journalist brought up “indiscriminate bombing of civilian targets, photo evidence provided by the defector codenamed Caesar … showing terrible torture and abuse in Syrian prisons”.

“Who took the pictures?” the president replied. “Who is he? Nobody knows. There is no verification of any of this evidence, so it’s all allegations without evidence.”

“But Caesar’s photos have been looked at by independent European investigators,” the journalist insisted.

“No, no. It’s funded by Qatar, and they say it’s an anonymous source. So nothing is clear or proven. The pictures are not clear which person they show. They’re just pictures of a head, for example, with some skulls. Who said this is done by the government, not by the rebels? Who said this is a Syrian victim, not someone else? For example, photos published at the beginning of the crisis were from Iraq and Yemen ...”

One of Caesar’s associates, a former paediatrician, has made a dossier classifying the different types and degrees of abuse to which prisoners have been subjected. “How did these people become anonymous numbers?” he said. “We must give these victims their identities back. Their families have a right to know what happened.” He is frustrated that these photographs have not produced any tangible result. What are the politicians doing, he wants to know. And the international community? “We thought our work would mobilise public opinion. The photos were shown to the EU, to Congress in Washington, to the UN Human Rights Council. But the politicians want to turn the page and negotiate with Bashar al-Assad. How did we get to that point?”

• Translated by Phil Daoust

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