The unwitting star of this year’s edition of Documenta, Germany’s leading art festival, was not an artist, but a former intelligence agent, Andreas Temme. Temme, who now works in the personnel department of the local government in Kassel, where the art festival takes place, was arrested 11 years ago in connection with the murder of Halit Yozgat. A son of Turkish immigrants, Yozgat was shot and killed while sitting at the front counter of his family’s internet cafe on the evening of April 6, 2006. Although the police cleared Temme as a suspect after a nine-month investigation — and a neo-Nazi terror cell calling itself the National Socialist Underground, or NSU, later claimed responsibility for the murder — Temme’s presence at the scene of the crime, at a time when he was employed by a regional intelligence service to monitor right-wing extremists, has never been fully explained. Yozgat’s family is not alone in suspecting that the domestic intelligence agency Temme worked for — the state of Hesse’s Office for the Protection of the Constitution, known as the Verfassungsschutz — has been engaged in a cover-up since 2006. The Kassel police detective in charge of the murder investigation, Helmut Wetzel, told a parliamentary inquiry in 2015 that the state’s intelligence service had refused to let his officers question any of Temme’s contacts in the local neo-Nazi scene, including a paid informant Temme had spoken with by phone shortly before entering the cafe that evening. Rather than act to dispel fears of a cover-up with full public disclosure, the intelligence agency has taken the opposite approach. In 2012, the state’s interior minister ordered a secret internal review of why Temme and other agents with confidential sources within the local neo-Nazi scene had failed to realize that Yozgat was the ninth victim in a nationwide killing spree carried out by white supremacist terrorists. When that report was completed in 2014, after a review of 3,500 files, senior intelligence officials ordered that portions of it should be kept from public view for 120 years. Local legislators, who stumbled across a heavily redacted version of the document during oversight hearings, were not even notified of its existence. The possibility that a German intelligence agency was, and still is, hiding something about the most deadly neo-Nazi terror cell to have operated inside the country since the Second World War briefly made Temme a household name across Germany. But attention to the case waned in recent years, as journalists attempting to gain new information have run into a brick wall of official silence. The case attracted a new level of scrutiny this summer, however, when a skeptical analysis of Temme’s testimony, based on leaked police files, became the most-talked-about piece at Documenta, an event that hosted 800,000 visitors between July and September.

The installation “77sqm_9:26min” confronted visitors to this year’s Documenta art festival in Kassel, Germany with a counter-investigation of the testimony of Andreas Temme, a German intelligence agent who claims to have seen and heard nothing at the scene of a neo-Nazi murder in 2006. Photo: Mathias Völzke/documenta 14/Forensic Architecture

The three-screen video installation probing Temme’s version of events was not a work of imagination, but rather a rigorous scientific investigation of whether he could have been in the cafe during the murder, as the police still believe, and somehow failed to either hear the shots or see the body. The investigation was conducted by Forensic Architecture, a team of experts in spatial analysis based at Goldsmiths, University of London, who have previously evaluated evidence of human rights abuses and potential war crimes in Palestine, Syria, Pakistan, Cameroon and Mexico. The mystery surrounding Temme’s visit to the cafe that evening — he logged in to a computer in the back room less than 15 minutes before Yozgat was fatally shot twice in the head from close range — starts with the question of why he fled the scene and failed to report to the police as a witness after news of the murder broke. When the police tracked him down — the intelligence agent had logged in to the dating site iLove.de from a computer in the cafe under the pseudonym “wildman70,” but also typed in his real phone number — Temme said that he had failed to give evidence because he had seen and heard nothing of the crime, and was embarrassed to have been there flirting online while his pregnant wife was at home. It was also possible, Temme said, that he might have left the cafe seconds before the killing, since he was certain that he had not heard any gunshots while sitting in the back room and had not seen Yozgat’s body lying on the floor behind the front desk when he placed a coin on it and walked out. Computer records from the cafe available to the police, however, showed that Temme had logged out of PC-2 in the cafe’s back room at 5:01:40 p.m. that evening. By comparing metadata from all the computers and phones in use in the cafe that evening with the statements of witnesses who heard loud sounds corresponding to two gunshots fired through a silencer, detectives concluded that the murder most likely occurred about 20 seconds before Temme logged out. Despite the fact that Temme’s story failed to convince the police — one detective called his account “incomprehensible” in court — the murder case against him was dropped for want of evidence after nine months. When it later emerged that Yozgat had been the ninth victim in an anti-immigrant killing spree carried out by the neo-Nazi National Socialist Underground between 2000 and 2006, Temme’s presence in the cafe that evening fueled speculation that the intelligence service might have had advanced warning of the terror cell’s plans, but still failed to prevent the murder. The lack of a convincing explanation for what Temme was doing at the scene of the crime also prompted darker speculation. “The government’s intelligence agent either killed my son, or he saw the murderers,” the victim’s father, Ismail Yozgat, said at a memorial service for Halit in April.

Photo: Forensic Architecture

For a modern state , officially committed to multicultural living, in which rights are bestowed on citizens equally, regardless of their national or ethnic origin, Germany is struggling to explain how its security apparatus failed for more than a decade to stop the NSU before the neo-Nazis killed nine ethnic minorities, detonated two bombs in immigrant communities, killed a police officer, and carried out 15 armed robberies.

Photo: Police Handout/DAPD

In fact, the intelligence failure was more profound than not stopping the NSU attacks: it extended to not even suspecting that right-wing extremists were behind the killing spree. Before November 2011, when two members of the cell, Uwe Mundlos and Uwe Böhnhardt, killed themselves following a botched robbery, and the third, Beate Zschäpe, turned herself in, the German police had spent years pursuing the theory that all nine murders were somehow connected to the Turkish underworld. The special police investigation of what the German media had called the “döner murders,” in reference to the kebabs sold by Turkish immigrants, was even code-named “Bosporus,” after the strait that separates Europe from Asia. One week after Yozgat’s murder in 2006, the head of the Bosporus unit told the media that he could see “no connection” between the victims (eight of them had family roots in Turkey, one in Greece).

Photo: DAPD News Agency

When the police searched the hideout in eastern Germany that Zschäpe had shared with Mundlos and Böhnhardt, however, they found the gun used in all nine racist murders, a Ceská 83 pistol. They also found copies of a bizarre confessional video made by the neo-Nazis, in which they used images from old Pink Panther cartoons to take credit for the terror attacks on immigrant communities across Germany over the previous decade. After years of police efforts to find killers with Turkish roots, the revelation that the murders were instead the work of German neo-Nazis prompted an apology to the victims’ families from Chancellor Angela Merkel, who promised a full accounting of who was involved in the crimes, and how the investigation had gone so far off-track. “Most of you were abandoned in your time of need,” Merkel told the victims’ relatives at a memorial service in Berlin in 2012. “Some relatives were themselves for years suspected of wrongdoing,” she said. “That is particularly oppressive. For this, I ask for your forgiveness.” More than five years later however, as Zschäpe’s trial grinds to a conclusion, and Merkel’s Christian Democrats find themselves hemorrhaging support to the anti-immigrant far-right, the authorities seem eager to move on, leaving unanswered the most uncomfortable questions about the intelligence failure and possible cover-up. In the Munich court where Zschäpe and four accomplices accused of aiding the terrorist group are on trial, the presiding judge, Manfred Götzl, has limited the scope of the inquiry. Specifically, the judge excluded questions about whether Germany’s 17 domestic intelligence services — the federal Verfassungsschutz and the independent agencies in each of the country’s 16 states — many of which maintain networks of paid informants inside neo-Nazi circles, knew the cell existed but failed to inform the police. Evidence presented in court, and to federal and state-level parliamentary inquiries, has revealed that dozens of neo-Nazis across Germany were on the payroll of various intelligence agencies during the NSU killing spree. As Stefan Aust, Helmar Büchel and Dirk Laabs reported, one of the terrorists, Uwe Mundlos, even worked for a construction firm owned by an informant in 2001, when three of the murders took place.

Photo: Tobias Hase/picture-alliance/dpa/AP

Lawyers representing 95 victims or relatives of those killed by the NSU have said since the trial began in 2013 that justice will not be served if the process simply results in a life sentence for Zschäpe without providing answers as to how and why their husbands, fathers, or brothers were targeted, and — most importantly — what German intelligence officials knew of the cell at the time. Osman Tasköprü, whose brother Süleyman Tasköprü, a grocer in Hamburg, was murdered by the neo-Nazi terrorists in 2001, told Turkey’s Anadolu news agency in July that Zschäpe’s trial was “not uncovering the facts. Everything is being hidden.” Not enough had changed since his brother’s murder, Tasköprü said. “At the time, the German state, the public, and the police pointed their fingers at us. No one deemed it necessary to investigate xenophobia. No one talked of far-right groups. They only pressured us,” he recalled. Tasköprü was among the relatives of the victims Merkel invited to Berlin in 2012. “We sat at the same table. She told us that they wanted to enlighten the entire matter. She is yet to keep her promise,” he said. Some of Merkel’s colleagues in the German Parliament, the Bundestag, agree that the intelligence services have failed to come clean about why they didn’t stop the NSU. A Bundestag investigative committee reported in June that the intelligence services had obstructed investigations of the murders to protect their paid informants. One of the authors of the Bundestag committee’s report, Irene Mihalic of the German Green Party, told Deutsche Welle that the federal Verfassungsschutz had made a “deliberate and specific” decision to shred files with information provided by neo-Nazi informants on November 11, 2011, one week after Zschäpe surrendered. The official who had destroyed the files, testifying to federal prosecutors in 2014 under an assumed name, said he did so to spare the intelligence services from having to answer difficult questions about why so many neo-Nazi informants had apparently failed to report the terrorist activities of Mundlos, Böhnhardt, and Zschäpe. “Destroyed files can’t be checked,” he explained. Even the chair of the Bundestag’s investigation, Clemens Binninger of Merkel’s Christian Democratic Union, said that evidence available to the inquiry suggests that the terror cell had more than three members — meaning that neo-Nazis involved in the murders have been allowed to walk free. “There is a slew of evidence that suggests that there must have been co-perpetrators at the scene, who helped or acted as lookouts,” Binninger told the Frankfurter Rundschau, a German daily, last month. “We have a situation where central questions of the victims’ relatives, ‘Why was my husband, my brother, our daughter killed?’ remain unanswered,” said another member of the committee, Petra Pau of the Left Party. In the specific case of Halit Yozgat’s murder, Helmut Wetzel, the detective who led the Kassel police department’s investigation, told a committee of the Hesse state parliament in 2015 that, in his view, the local intelligence agency was protecting a liar. “I think Temme witnessed the act,” Wetzel said. The detective added that senior officials in the state’s intelligence agency had not taken seriously the need for a full police investigation of its agent. Wetzel also heaped scorn on Temme’s claim that, at the time of Yozgat’s murder, no one in the intelligence service suspected that Yozgat and the previous eight victims killed with the same gun had been targeted by right-wing extremists. “You did not have to be a clairvoyant to understand that this was a xenophobic crime,” Wetzel said. Frustrated by the failure of the German state to deliver the full accounting Merkel had promised, advocates for the families have taken it upon themselves to keep prodding the authorities for answers. One such initiative was a People’s Tribunal, dedicated to unravelling what civil society activists call “the NSU complex,” by which they mean both the extent of the terror cell’s network and the structural racism in German society that allowed the nationalist terror cell to go undetected for so long. Before the tribunal convened in Cologne in May, near the site of an NSU nail bomb attack that wounded 22 people in 2004, the group commissioned Forensic Architecture, a team of seasoned investigators (and a publishing partner of The Intercept) to conduct a fresh examination of the ninth murder in the series — the killing of Halit Yozgat. The team, led by architects from Israel and Greece, Eyal Weizman and Christina Varvia, had previously used architectural modeling to analyze open-source evidence of potential violations from drone strikes in Pakistan; American, Russian, and Syrian air raids in Syria; the torture of prisoners in Cameroon; and attacks on protesters in Palestine. In this case, to conduct a counter-forensic examination of Temme’s claim that he neither heard nor saw any evidence of the killing, the researchers from Forensic Architecture used leaked files from the original police investigation, including witness testimonies, computer and phone logs, crime scene photographs and, most importantly, a police video showing Temme re-enacting his exit from the internet cafe in 2006. In Weizman’s view, if Temme was lying when he demonstrated for the police how he left the cafe without observing anything out of the ordinary, the video itself might be considered evidence of a crime: perjury. “In our office, usually we look at video of bombs falling in Gaza or in Iraq or in Syria, and we undertake a very, very close analysis of the video,” the architect said at a public presentation of the investigation in May. “We are looking here, potentially, at an alleged crime as it is taking place,” he added. The researchers also interviewed the victim’s father, Ismail Yozgat, who described the exact position of his son’s body on the floor behind the counter when he saw that his son had been murdered.

This independent analysis of Temme’s testimony seemed necessary to the Yozgat family because the sealed intelligence report on the former agent’s presence at the crime scene has obscured key aspects of what led to the murder, and whether it could have been prevented by the state. The police investigation of Temme was hampered from the start by his status as an intelligence agent. Officers who arrived at his home two weeks after the murder did not immediately search it for evidence once he revealed that he was with the Verfassungsschutz. The police subsequently found a cache of guns in Temme’s home — and Nazi literature and regalia, including sheets of paper with quotes from “Mein Kampf” that he had typed out as a young man. But the officers were denied permission to question the neo-Nazi informant Temme had spoken with less than an hour before the murder of Yozgat. The police request to speak with the informant was ultimately blocked by the interior minister for the state of Hesse at the time, Volker Bouffier, a senior figure in Merkel’s Christian Democratic Union, who cited a need to protect undercover sources. Bouffier, who apparently met Temme at a political event some years before Yozgat’s murder, is today the state’s first minister. The investigation of Temme as a suspect in the murder concluded nine months later, after he adamantly denied being a neo-Nazi — chalking up his interest in “Mein Kampf” to a since-faded youthful fascination with the Third Reich. But the detectives who questioned him have never been convinced by his claim to have heard and seen nothing. The lead detective in Kassel and a police analyst who prepared a report on the case in 2008 for the Bosporus investigation both concluded that the murder almost certainly took place while Temme was still sitting in the cafe. If Temme was in the cafe’s back room, still logged in to the dating site, when the murder took place, his version of events can only be truthful if he first failed to hear the shots being fired and then failed to notice Yozgat’s body lying on the floor behind the blood-spattered counter in the front room as he paused to leave a coin there before exiting. If, on the other hand, Temme did see the body and hear the shots, his presence at the crime scene could be the clearest evidence that a German intelligence service is still hiding its contemporaneous knowledge of the NSU’s killing spree.

To test Temme’s account of how he left the internet cafe without hearing or seeing anything out of the ordinary, the Forensic Architecture team conducted a series of sensory experiments based on the leaked re-enactment video. The experiments, to establish what Temme should have been able to hear and see, were conducted both in computer simulations and in a full-scale replica of the internet cafe built at the House of World Cultures in Berlin in March.

The results of the audio experiments were clear: For an eighth of a second, each of the two gunshots would have produced a sound pressure in the back room close to 100 decibels, or as loud as a jackhammer breaking concrete in the front room. “The data from both the physical and digital tests confirmed that the sound level at Temme’s position at PC-2 was between 94 to 99 decibels at maximum level,” Forensic Architecture reported. “This is 40 to 45 decibels above the maximum ambient sound level that can be expected in such a space.”

The tests of what passed before Temme’s eyes after the shooting were even more compelling. Using the police re-enactment video and motion-detection software, as well as analog measures, the architects made a computer animation of Temme’s cone of vision as he left the cafe. The researchers then repeated the test in the physical model they had built in Berlin, with a camera attached to the head of an actor, to show clearly that Yozgat’s body would have been visible to a man of Temme’s height (nearly 6-foot-3, according to the local police) as he approached the counter and leaned down to leave a coin. When Forensic Architecture first presented its experimental findings in April, for the 11th anniversary of Yozgat’s murder, the work was praised in news reports across Germany, but a leader of Merkel’s Christian Democrats in Hesse, Holger Bellino, dismissed renewed suggestions that Temme had lied about not witnessing the murder as “another conspiracy theory.” The Forensic Architecture analysis, Bellino complained, had not examined the possibility that Temme might have left the cafe seconds before the killing — a scenario the police called unlikely. The Forensic Architecture team then added a section to their report that included an analysis of the estimated time of the murder and Temme’s exit from the cafe, based on the log-in data available to the Kassel police in 2006, which was leaked online in 2015. That longer version of the report was then featured in Documenta, the art festival in Kassel. The 27-minute video, “77sqm_9:26min,” was presented as a three-channel installation in the city’s old post office building, which is located only a few hundred yards from the scene of Yozgat’s murder. Forensic Architecture’s report, and the technical data underpinning it, was presented alongside other works documenting the impact of Yozgat’s murder, including video of a protest in Kassel one month after his death, in which thousands of members of the city’s immigrant community had marched through the streets, demanding the arrest of the killers responsible for the series of racist murders.

That demonstration, from a community that knew it was the target of racist terror attacks, underscores just how blind the police were to the most likely motivation for the murders at the time. “From September 2000 to April 6, 2006, nine independent business owners have been killed with the same weapon,” Ismail Yozgat, Halit’s father, said at the end of the march that day, outside Kassel’s City Hall. “How many executions have to be carried out before the perpetrators are caught?” He went on to accuse the local interior ministry of ignoring the suffering of the immigrant families. “Listen to the grief of the families. Try to put yourselves in our place. Try to understand what it means for my family to lose a child in the best years of his life,” Yozgat said. “If you do this, I believe you’ll feel our pain and you’ll understand our situation. We’re mourning for our son. And we don’t want others to have to mourn in the future.” Ayse Gülec, a founding member of the People’s Tribunal and the Society of Friends of Halit, remembers those who marched after Yozgat’s murder in 2006 feeling like “ghosts,” unnoticed by their neighbors and the authorities. “The politicians and also the police don’t care, that was the experience of this community,” she told The Intercept. “This is what we call structural racism.” Temme, reached by phone at his office in a local government building in Kassel, told The Intercept he had not visited the Documenta exhibit, but he considered it biased against him because it was commissioned by advocates for the families of NSU victims. When excerpts from the Forensic Architecture video were screened for him recently during a parliamentary inquiry into intelligence failures revealed by the NSU case, Temme’s first response was to express surprise that, as “the lead actor” in the re-enactment video used in “the art work,” no one had asked permission to use his image. Surely, he said over stunned laughter from the public gallery at the hearing, he must have some share in its copyright.

To conduct experiments on what Andreas Temme would have seen if he left the internet cafe after Halit Yozgat’s murder, Forensic Architecture built a full-scale replica of the space. Image: Forensic Architecture

After watching an excerpt where the sound level of the gunshots that killed Yozgat was demonstrated in Forensic Architecture’s full-scale model of the internet cafe, Temme said that he remained certain that he had not heard the shots and was unsure as to whether he was still in the cafe at the time. “Either I did not hear the sound, because I might have already left, or I did not notice it,” he said. “I would still like to know,” Temme added, “whether I was there or not.” Temme echoed that sentiment in his phone interview with The Intercept, saying that the question of whether he was present in the cafe when the shots were fired would perhaps never be answered. He also pointed out that Holger Bellino, a Christian Democrat deputy in the Hesse state parliament, recently criticized Forensic Architecture for using leaked files from the 2006 police investigation which included some faulty data. Bellino based his critique on more accurate records of the duration of phone calls made by other witnesses from inside the cafe that evening, contained in a previously secret 2008 federal police report.

However, the 2008 police report, which has been obtained by The Intercept and is published here for the first time, does not exonerate Temme. The data, and an accompanying police analysis, merely show that it is possible that the killing took place seconds after Temme left the cafe, but only if a series of events, for which there is no evidence, took place in rapid succession. Temme’s version of events — that he logged out from his computer, walked to the front room to pay, and, when he could not find Yozgat, placed a coin on the front desk and left — could only have taken place before the murder if Yozgat had gone for a walk outside, unseen by any witnesses, minutes before the shooting, and the killers had then followed him back inside, waited for him to sit back down behind the counter, shot him twice, and escaped, all within 65 seconds. The police analyst who prepared the previously unseen 2008 report, Gerhard Frese, had ruled out that scenario as unlikely. In testimony to the Hesse parliamentary inquiry last month, Frese said that, “in my personal opinion,” Temme, an experience marksman, must have heard the shots and then smelled the gunpowder when he stepped into the front room seconds later. Frese added that he was also “relatively certain” that the intelligence agent must have seen Yozgat’s body lying behind the counter as he leaned down to place a coin on a desk flecked with the victim’s blood. It is not clear why Bellino, the Christian Democrat legislator in Hesse, has worked so hard to sow doubt in Forensic Architecture’s findings by endorsing this unlikely scenario, but it is worth keeping in mind that police officers who have publicly accused Temme of lying have known about those records for nearly a decade. Joachim Börger, the former chief inspector of the local police force who interrogated Temme in 2006, told the Hesse public inquiry in August that he still found it difficult to believe that the intelligence agent had not seen Yozgat’s body. Another police source with direct knowledge of the initial investigation into Yozgat’s murder, who asked not to be identified because the NSU trial is still in progress in Munich, confirmed to The Intercept that the newly public phone records did not change his conclusion that the most likely scenario remains that Temme only logged out of his computer in the cafe about 20 seconds after the neo-Nazi killers, presumably Mundlos and Böhnhardt, burst through the front door and fired the fatal shots.

Photo: Sean Gallup/Getty Images