In 2014, Wiley restructured the CIJA’s Syrian team; as deputy chief of investigations, Mustafa now presided over all the group’s provincial cells. “He was very good at finding documents, and he understood evidence and law,” Wiley said. “But he was also respected by his peers. And he had a natural empathy, which translated into him being a very good interviewer” of victims and perpetrators alike. According to Omar, Mustafa often cut short his appearances at social gatherings, citing family or work. “I know it’s a cliché, but he really was a family guy,” Wiley told me. “But where he excelled in our view—because we don’t need a bunch of good family guys, to be blunt—is that he could execute.”

That July, Assad’s General Intelligence Directorate apparently learned of the CIJA’s activities, long before the group had been named in the press. In a document that was sent to at least ten intelligence branches—and which was later captured by the CIJA—the directorate identified Mustafa as “vice-chairman” of the group, and also listed the names of the leading investigators within each of the CIJA’s governorate cells. At the bottom of the document, the head of the directorate handwrote orders to “arrest them along with their collaborators.”

By now, Western governments, which had pledged to support secular opposition groups, found the situation in northern Syria unpalatable; there was no way to guarantee that weapons given to a secular armed faction would not end up in jihadi hands. Saadeddin had begun to lose hope in the revolution—a sentiment that grew only stronger when Assad’s forces killed more than a thousand civilians with sarin gas, and the Obama Administration backed away from its “red-line” warning of retaliation. “At that point, I lost all faith in the international community,” Saadeddin told me. “I felt that they didn’t want Syria to become liberated—they wanted Syria to stay as it was.” He moved into the defected officers’ camp in southern Turkey, where he remained—feeling “rotten,” consumed by a sense of impotence and frustration—for most of the next decade.

I first came into contact with the CIJA late in the summer of 2015. By that point, the group had smuggled more than six hundred thousand documents out of Syria, and had prepared a legal brief that assigned individual criminal responsibility for the torture and murder of thousands of people in detention centers to senior members of the Syrian security-intelligence apparatus—including Assad himself. In the following years, the CIJA expanded its operations to Iraq, Myanmar, Libya, and Ukraine. But Syria was always at the core.

“In terms of the opposition overrunning regime territory—that effectively ceased in September, 2015, when the Russians came in,” Wiley recalled. In the following years, Russian fighter jets pummelled areas under rebel control, while fighters from Russian mercenary groups, Iranian militias, and Hezbollah reinforced Assad’s troops on the ground. In time, the confrontation lines settled, with the country effectively carved into areas under regime, opposition, Turkish, and Kurdish control. But Mustafa and other investigators continued to identify troves of documents, scattered among various hidden sites. “We’d acquire them from different places, and then concentrate them,” Wiley said. Omar told me that it was best to keep files as close to the border as possible, to limit the chance of their being destroyed in the event that the regime took back ground. “Mustafa would sometimes spend a week or more prepping for document extractions,” Omar said. “He would sleep in tents,” in camps filled with other displaced civilians, “while he waited for the right moment to move the files closer to the border.”

At the CIJA’s headquarters, in Western Europe, the organization built cases against senior intelligence officers, like the double agent Khaled al-Halabi, and provided evidence to European prosecutors who were investigating lesser targets all over the continent. In recent years, Western prosecutors and police agencies have sent hundreds of requests for investigative assistance to the CIJA headquarters; when the answers can’t be found in the existing files, analysts refer the inquiries, via Mick, the Australian in southern Turkey, to the Syrians on the ground. “We wouldn’t tell them who’s asking, or who the suspects are,” Wiley said. “We’d just say, ‘O.K., we’re interested in witnesses to a particular crime base’—a security-intelligence facility, a static killing, an execution, that kind of thing. And then they would identify witnesses and do a screening interview.” When requests came through, Mick told me, “Mustafa was usually the first team member that I went to, because his networks were so good.”

During the peak years of the pandemic, Mustafa identified and collected witness statements against a trio of Syrian ISIS members who had been active in a remote village in the deserts of central Syria and were now scattered across Western Europe. All three men were arrested after his death.

Perhaps Mustafa’s most enduring contribution to the CIJA’s casework is found in one of the group’s most comprehensive, confidential investigative briefs, which I read at the headquarters this spring. It’s a three-hundred-page document, with almost thirteen hundred footnotes, establishing individual criminal responsibility for war crimes carried out during the regime’s 2012 siege of Baba Amr, a neighborhood in the southern part of Mustafa’s home city, Homs. Other cases have centered on torture in detention facilities; this is the first Syrian war-crimes brief that focusses on the conduct of hostilities, and it spells out, in astonishing and historic detail, a litany of crimes, ranging from indiscriminate shelling to mass executions of civilians who were rounded up and killed in warehouses and factories as regime forces swept through. The Homs Brief—for which Mustafa collected much of the underlying evidence—also assigns criminal responsibility to individual commanders within the Syrian Army’s 18th Tank Division, which carried out the assault.

“He thought he was contributing to a better Syria,” Wiley said. “When—and what it would look like—was unsure. But he believed in what he was doing. He could have fucked off years ago. We probably could have gotten him to Canada. We talked about it, because one of his daughters had a congenital heart issue.” Nevertheless, he stayed.

Last year, Mustafa bought an apartment on the eleventh floor of a new tower block in Antakya. Rula’s aunt moved into the same building, a couple of stories below. Her parents left the defected officers’ camp and moved into another apartment block, a short walk up the road. A few months later, Mick recalled, “Mustafa said to me, ‘When I’m at home with my family, it doesn’t matter what’s happening outside—it doesn’t matter if there’s a war. When I’m at home, I’m at peace.’ ”

Last December, Mick was visiting Mustafa’s apartment when the floor began to shake. “It spooked me—it was my first time feeling this kind of tremor,” Mick recalled. Mustafa laughed and said that they happen “all the time.” Then he went to check on Rula and the children, who reported that they hadn’t even felt it.

A couple of months later, Mick awoke to news of the catastrophic earthquake and tried to call members of his Syrian team. But the cellular networks were down in Antakya, and it was impossible for him to travel there, because the local airport’s runway had buckled, along with many local roads.

Saadeddin’s sister was dug out of the complex alive; her husband survived as well, but died in a hospital soon afterward, without anyone in the family knowing where he was. On the fourth day of search-and-rescue operations, Mustafa’s passport was found in the rubble. Then his laptop, then his wife’s handbag. “When they found the bodies,” Omar said, “Mustafa was hugging his daughter, his wife was hugging their son, and the other two children were hugging each other.”

Omar spent the next several days sleeping in his car, along with his wife and six children. Thousands of aftershocks shook the region, and, by the time I met with him, a few hundred metres from the Syrian border, he was so rattled that he reacted to everyday sounds as if they might signal a building’s collapse. His breath was short and his eyes welled with tears; Mustafa had been one of his best friends, and he had also lost eleven relatives to the quake, all of whom had been displaced from the same village in northern Syria. Then his young son walked into the room, and he turned his head. “We try to hide from our children our fear and our grief, so that they don’t feel as if we are weak,” he said.

A few weeks after the earthquake, there was an empty seat at a prestigious international-criminal-investigations course, in the Hague. Mustafa had been scheduled to attend. “We can mitigate the effects of war, except bad luck, but we didn’t factor an earthquake into the plan, institutionally,” Wiley told me. Mick coördinated humanitarian assistance for displaced investigators, and, as Wiley put it, “the operational posture came back really quickly.” Omar has now taken over Mustafa’s leadership duties. “Keep in mind how resilient this cadre is,” Wiley continued. “They’re already all refugees, perhaps with the rare exception. They had already lost their homes, lost all their stuff.”

It was the middle of April, more than two months after the quake. Much of Antakya had been completely flattened, and what still stood was cracked and broken, completely abandoned, and poised to collapse. Mick and I made our way through the old city on foot; the alleys were too narrow for digging equipment to go through, and so we found ourselves climbing over rubble, as if the buildings had fallen the day before. The pets of those entombed in the collapsed buildings followed us, still wearing their collars—bewildered, brand-new strays. ♦