dil Öksüz first came to the attention of Turkish authorities when a shepherd called local officials to report a suspicious sight.

It was the morning after Turkey’s failed coup in July 2016. The shepherd was tending his flock by the crater-lined runway of Akıncı Air Base, northwest of Ankara. Throughout the night, departing rebel jets had roared off as they raced toward the capital. Their airstrikes killed dozens of people in Ankara, and stopped only when government forces bombed the tarmac two hours after sunrise.

So the shepherd was alarmed when, not long after the dust had settled, he spotted a man in civilian dress, accompanied by several soldiers, attempting to slip past the wire fence surrounding the base and into the wheat fields beyond.

The gendarmerie swooped in and arrested the group before it could reach the road. Öksüz, the man in civilian clothing, was a theology professor at Sakarya University near Istanbul. The explanation he offered for being near the air base was scarcely believable: He said he had been looking at land to purchase.

Other details in his story also raised suspicion. No taxi driver would corroborate Öksüz’s claim that he had taken a cab to the air base that morning. The addresses he listed in his statements to the court would later be found to be abandoned.

State prosecutors asked that the professor be placed in custody. Instead, two days after he was picked up, Öksüz was set free. The judge who signed the order would later admit to being a follower of Fethullah Gülen, the Pennsylvania-based cleric the Turkish government blames for the attempt to overthrow President Recep Tayyip Erdoğan.

The soldiers detained with him — like hundreds of other officers captured across the country — remained in custody.

Weeks later, the Turkish government would name Öksüz as the man who organized the failed takeover on Gülen’s behalf. By then, he had long disappeared — slipped out of the country, authorities believe, possibly to Germany or elsewhere in Europe.

Dubbed by the Turkish press as the “runaway imam,” Öksüz ranks among Turkey’s most-wanted men. And with good reason. Should he be captured and brought to testify, he could provide the government with its most solid evidence yet that Gülen masterminded the failed coup.

Ankara maintains that Öksüz served as the main liaison between Gülen and those that carried out the attempt, shuttling back and forth between Turkey and Pennsylvania to receive and transmit orders from the cleric.

He is the government’s best chance at proving its claims — and a chance to win over key Western allies that have yet to be convinced that Gülen was personally involved. The United States government says it has not received enough evidence to warrant the 76-year-old preacher’s extradition.

“We know Adil Öksüz had an important role in the coup attempt of July 15, we know he is a key name,” Turkish Prime Minister Binali Yildirim told reporters in March. “But unfortunately he is on the run.”

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t’s very likely that Öksüz is a Gülenist, as the cleric’s followers are known. Gülen told France 24 in July 2017 that Öksüz belonged to one of the movement’s study groups when he was a student “around 30 years ago,” and he had come to his compound in Pennsylvania “a few years ago,” but did “not know” if he had returned the July before the coup. Gülen did not respond to POLITICO’s request for comment.

On the surface, Öksüz, 50, lived an unremarkable life: Born in a village in the Taurus Mountains, he studied theology and rose to become an assistant professor at Sakarya University, a two-hour drive from Istanbul. He married, had two children and published nothing but his dissertation. His mugshot, taken on the morning he was detained at the air base, shows a balding man with a faint mustache.

Yet, Öksüz’s travel history appears extravagant for the modest income of a provincial academic. In the past decade and a half, Öksüz reportedly traveled abroad more than 100 times, often to the U.S. By the end of June 2016, less than three weeks before the failed coup, he had already jetted stateside twice that year.

At the beginning of July, the government gave all public sector employees nine days off work to celebrate Eid al-Fitr, the holiday marking the end of the Muslim fasting month of Ramadan.

State prosecutors say Öksüz used this time to summon his military co-conspirators to a villa in Ankara to finalize the plot — an accusation that rests on the testimony of two dismissed officers codenamed Şapka (“hat”) and Kuzgun (“raven”), who say they witnessed the meeting.

The statements are crucial to the government’s case against Öksüz, but there are reasons to doubt their reliability: Gareth Jenkins, an independent analyst in Istanbul who has written extensively on the coup attempt, notes the information Şapka divulged was already circulating in the public domain by the time he appeared in court. Kuzgun, too, had little to add.

Shortly after this meeting allegedly took place, Öksüz made yet another trip to the U.S. On July 11, four days before parts of the Turkish military rose up against Erdoğan, he boarded a Turkish Airlines flight from Istanbul Atatürk Airport to New York JFK.

He was seated in business class. Businessman Kemal Batmaz — another prominent Gülenist who would also later be caught near Akıncı Air Base — sat several rows behind him in economy.

The government claims it was during this trip that Öksüz received Gülen’s final approval for the coup. It was a whirlwind visit: On July 13, both Batmaz and Öksüz returned to Turkey, once again aboard the same flight.

Two days later, tanks blocked Istanbul’s Bosphorus Bridge, soldiers surrounded Taksim Square, and from Akıncı Air Base, fighter jets took off to bombard Turkey’s parliament.

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he air base where Öksüz was picked up lay at the heart of the attempted coup. Loyalist generals taken hostage that night — including Hulusi Akar, the chief of general staff — were brought there to be held. Several civilians with ties to Gülen were arrested nearby the next day.

Öksüz seems to have taken an interest in Akıncı long before the coup attempt. According to phone signal data obtained by state prosecutors, the theologian visited the area a dozen times between December 2015 and June 2016.

This, state prosecutors say, is proof that he was the Gülenist movement’s “imam of the air force” — the group bestows the title “imam” on those responsible for organizing its followers in a country, profession or other group.

And yet, evidence placing Öksüz at the base at the time of the coup is scarce. Dozens of officers were present at the base that night, but in subsequent court appearances, only three people said they had seen him.

None offered much detail. Base Commander Hakan Evrim testified that he had spotted Öksüz at some point during the night. Müslim Macit, a pilot who had dropped bombs on Ankara’s presidential complex, told a court last year: “I saw a person who looked like Öksüz.” A third officer, helicopter pilot Uğur Kapan, retracted his statement in a court appearance this summer, saying that his earlier testimony had been extracted under torture.

In any case, by the time Öksüz was captured near the base’s perimeter, the coup had failed. Thousands of citizens had taken to the streets in protest, facing off against tanks and guns. Some 250 people had been killed, plus an unknown number of soldiers on the plotters’ side.

Erdoğan was quick to name a culprit: the Gülen movement. To most Turks, the group seemed the most likely candidate; after all, the cleric’s followers were known to have infiltrated state institutions before and after Erdoğan’s rise to power. Turkey’s quasi-official Anadolu news agency informed its readers that the man who had led the coup attempt was Muharrem Köse, a colonel who had been dismissed months earlier. A manhunt began.

Öksüz was not yet on the government’s radar. Released on July 18, he walked out of the courthouse and made a beeline for the airport, boarding a plane to Istanbul. The next day, state investigators later found out, a cell tower located Öksüz’s phone in Sakarya, where he lived and taught.

That same day, Muharrem Köse was detained. “Coup planner arrested!” the headlines read.

In the following weeks, the government would conclude that Köse was probably not the ringleader and turn its attention on Öksüz. It offered no explanation for the shift. In any case, by then the theologian was long gone.

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ksüz’s mysterious disappearance unleashed wild speculation in Turkey over his allegiances and whereabouts. He has been supposedly spotted across all of Europe, from Georgia’s Black Sea resort town Batumi to London’s Portobello Market. (The latter was a lookalike.)

Pro-government columnists quickly labeled the theologian a CIA agent and felt vindicated after local media reported that the U.S. Embassy in Ankara had called Öksüz on July 21, two days after his vanishing act. He never picked up.

The U.S. Embassy says it made a routine call to inform Öksüz that his visa had been canceled. But to conspiracy theorists, it was proof enough — especially when, a month after the coup attempt, USA Today reported that a company registered by Öksüz had donated $5,000 to a Hillary Clinton campaign group in 2014.

Newspapers have dubbed Öksüz the “black box” of the coup attempt, the man holding all information on the plot. Columnists and analysts close to the government have speculated that he may have been not just the Gülenists’ leader in the air force, but the “imam of the entire army.”

Turkey’s Western allies are unimpressed. European intelligence agencies doubt Gülen masterminded the coup.

A report by the EU Intelligence Analysis Centre, which analyzes information provided by EU countries’ intelligence and security services, leaked to the Times of London, posits that the conspirators are not all Gülenists. Instead, the report concludes, the plotters are likely a loose coalition of dissatisfied officers that includes Gülenists but also secularists, opportunists and government opponents of all stripes.

“It is unlikely that Gülen himself played a role in the attempt,” says the August 2016 report. (Turkey called the report “biased.”)

Bruno Kahl, the head of Germany’s intelligence service BND, says he does not believe Gülen was involved in the coup attempt. “Turkey has tried to convince us of that at every level but so far it has not succeeded,” he told Der Spiegel in March.

The U.S. too, remains unconvinced by Ankara’s evidence. “We haven’t seen [proof] yet,” National Intelligence Director James Clapper said shortly after the coup. “We certainly haven’t seen it in intel.”

Asked about Turkey’s extradition request in September, a U.S. State Department spokesperson said, “We continue to evaluate it, take a look at the materials that the Turkish Government has provided us. I don’t have anything new for you on the subject of that.”

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kepticism from abroad has added urgency to Turkey’s attempts to locate Öksüz. This summer, the country’s newspapers became fixated on the idea that he was living in Germany. Reported sightings in Hanover, Frankfurt and Ulm eventually prompted the Turkish government to take action.

In August, Ankara handed Germany a diplomatic note demanding the theologian’s extradition. Erdoğan said he expected Berlin to “take the necessary steps” regarding Öksüz.

Martin Schäfer, a German foreign ministry spokesman, told reporters in August that the government would look into it, adding there was no proof of Öksüz’s presence in Germany.

If the fugitive theologian were to resurface in Germany, it would put yet another dent in strained Turkish-German relations. The Turkish government defines Gülen’s movement as a terror group, and Germany granted asylum to hundreds of suspected Gülenists this year.

The Öksüz case has also damaged U.S.-Turkish ties. In October, Turkey arrested a local employee of the U.S. Consulate in Istanbul, accusing him of espionage and threatening the constitutional order.

Erdoğan’s spokesman Ibrahim Kalin told reporters: “The arrested U.S. consulate worker was found to have had frequent communication with the Gülenist suspect Adil Öksüz.”

Washington condemned the allegations as baseless, and in retaliation U.S. diplomatic missions in Turkey have suspended the processing of non-immigrant visas. Ankara responded in kind, halting visa processing in its embassy and consulates in the U.S. and shutting down e-visa services for American citizens.

In its pursuit of suspected Gülenists, Ankara is evidently prepared to risk foreign relations and its economy. (The Turkish lira has taken a nosedive against the dollar since the beginning of the diplomatic spat with the U.S.) The Turkish government is desperate to prove its version of the events, and Öksüz’s involvement lies at the heart of its argument.

After all, the post-coup purge, in which tens of thousands have been arrested for alleged links to Gülen, relies on the assumption that the cleric’s movement is solely responsible.

And yet, Öksüz aside, the government’s case against the Pennsylvania-based cleric rests largely on a statement by Chief of General Staff Akar, who claimed a rebel officer offered to put him in touch with Gülen. The officer denied the accusation.

Without testimony from Öksüz, the evidence tying Gülen to those who carried out the coup is weak. The purpose of the theologian’s trip to the U.S. in July 2016 is unknown. There is no evidence he visited Gülen in Pennsylvania ahead of the coup, and there’s little proof he was the “imam” of the air force.

As long as Öksüz remains missing, Ankara’s claims are hard to prove — and to disprove. “It’s very easy to say he was absolutely central,” says Jenkins, the analyst. “Because you can’t question him.”

Erdoğan should be careful what he wishes for. Öksüz’s capture would not be without risk. If the government fails to pin down his participation in the attempted coup, its case against Gülen might start to unravel.

“If he wasn’t involved, if there is some innocent explanation — it’s difficult to think, but if there is — the whole government narrative just collapses,” says Jenkins.

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