Members of the Syrian Democratic Forces commandos unit in Dashisha in Syria's Hasakah province in 2021. (Nicole Tung for The Washington Post)
The surveillance footage was alarming. Though grainy and inconclusive, it captured the nighttime movements of someone creeping into the ammunition storage area at a remote U.S. outpost in Syria. An hour later, twin explosions there wounded four Americans and ignited a fire that burned until daylight.
A military investigation into the April 2022 incident led to the arrest of Tech. Sgt. David W. Dezwaan, an Air Force explosives expert found alone at the second blast site. Military prosecutors would later allege that he had both the skills and access to equipment needed to stage an insider attack.
The highly unusual allegation of betrayal went to court-martial earlier this year, resulting in Dezwaan's acquittal after an eight-day trial in Utah. Prosecutors called him a saboteur, possibly disillusioned by the deployment to an outpost where some fellow troops viewed him as strange. Dezwaan's lawyers said the case was full of holes, and a jury ultimately agreed.
An investigation case file obtained by The Washington Post through the Freedom of Information Act reveals what Dezwaan's lawyers criticized as a dearth of credible forensic proof and motive linking him to the bombings. The file also exposes how broader security concerns at the compound, which U.S. personnel share with Syrian partner forces, raised doubt among the jury members.
And so the identity of whoever slipped past the cameras, locks and guard posts may never be determined.
Dezwaan, an explosives disposal technician, remains in the military. He declined an interview request. His attorneys, Nathan Freeburg and Philip Cave, emphasized the concerns shared by some witnesses about security gaps at the outpost.
It was "easy," Cave told The Post, for members of the Syrian Democratic Forces (SDF) to access the Americans' side of the camp, known as Green Village. "It could just as easily have been someone from the SDF or even someone who had infiltrated the SDF," he said, pointing to a history of such incidents in Afghanistan that have nevertheless been rare in Syria. "And when the investigations were done, nobody was allowed to interview the SDF people. That's a big hole."
Farhad Shami, an SDF spokesman, called such a theory "entirely untrue," noting that its personnel are not allowed access to the ammunition area where the explosions occurred and that the surveillance video's field of view indicated that whoever did so approached from the U.S. side.
"Yes, there is high coordination and positive cooperation between us and the coalition forces in the Green Village, but there are still privacy and security controls that we and the coalition abide by," Shami said.
An Air Force spokeswoman, Rose M. Riley, said the investigation, conducted by Army and Air Force law enforcement, did not "develop information" indicating an SDF member was responsible for the explosions.
U.S. Central Command, which oversees military operations in the Middle East, declined to comment on the alleged security lapses, citing "operational security."
Approximately 900 troops — mostly U.S. Special Operations teams — are deployed in eastern Syria supporting the SDF, a predominantly Kurdish militia, as they endeavor to prevent a resurgence of the Islamic State group. Green Village, in the oil-rich Deir al-Zour province near the Iraq border, has been a magnet for harassment by Iranian-backed militias and their allies in the Syrian government eager to expel the Americans.
Green Village and other U.S. outposts in Syria are routinely struck by rockets and drones. In March, a burst of deadly violence between U.S. forces and suspected Iranian proxies led President Biden to warn Tehran there would be severe consequences for violent attacks on American troops.
SDF members guard a prison complex in Hasakah in February 2022. (Nicole Tung for The Washington Post)
'That doesn't sound like me'
The first blast struck the Green Village ammunition area at 1 a.m., ripping through captured enemy explosives, rockets and grenades, and shooting debris 1,000 feet into the air. A minute later, a smaller explosion hit a shower trailer, wounding Dezwaan as he approached for a late-night rinse. In addition to his toiletries, he had a knife and a butane lighter, according to his interview summary.
Explosive charges were placed at both sites, an analysis determined. Each was rigged with simple timers, such as black powder fuses, and possibly ignited by a handheld lighter. Dezwaan, investigators noted, consented to a phone search where they found that a stopwatch app had been running up until the explosions. Lab tests performed around the shower revealed traces of RDX and PETN, compounds used widely in plastic explosives.
Dezwaan was the only American missing after the blasts. He was found crawling between shower trailers wearing shorts and a T-shirt, lightly wounded but apparently stunned by the explosion, witnesses told investigators.
A medical examiner determined that Dezwaan's injuries were not consistent with blast wounds, leading prosecutors to argue that he cut himself using a charred knife found at the scene, though no DNA was recovered. Dezwaan's attorneys said he was cut crawling through debris and that an MRI showed he had a mild traumatic brain injury.
The four Americans hurt in the blast all suffered head injuries. As they boarded a helicopter for follow-on medical care in Baghdad, another explosives expert assigned to Green Village joked about Dezwaan being the culprit, witnesses told investigators. Citing a dark sense of humor, he later clarified that did not believe Dezwaan "would blow himself or anyone else up."
Other explosives experts interviewed by investigators said Dezwaan had been excited about the Syria assignment, though his team hadn't been very busy.
Some troops cast suspicion on Dezwaan, though, telling investigators he was "weird." Several described minor altercations they had with him — a disagreement over seating in a dining area and a dispute over photos he'd taken of a separate unit's living quarters. One witness said Dezwaan appeared upset to be overseas on his birthday, and at trial, prosecutors argued that he sought to go home early.
When investigators asked Dezwaan about inconsistencies in his story — including contradictory comments he made about being inside, rather than outside, the trailer during the attack — he said his memory had been distorted by the brain injury he sustained.
The last thing Dezwaan said he remembered was working late on paperwork, which other troops said was normal, the investigation shows. But he maintained that he would not have planted bombs: "I know myself," he told investigators. "That doesn't sound like me."
A 'whodunit'
While U.S. forces and their Syrian partners have worked closely for years to dismantle the Islamic State's self-declared caliphate, the investigation documents some friction, distrust and frustration with perceived security lapses.
For instance, weeks before the explosions at Green Village, an SDF member who had been banned from the base was seen visiting the SDF liaison house after somehow having made his way back inside, witnesses told investigators. It's unclear why the man had been barred; that portion of the case file is redacted.
In another incident, the report says, SDF crews drove onto the outpost hauling a primed roadside bomb. The Americans hadn't expected the delivery and were surprised the SDF was able to "deliver it right to them without being stopped," an investigator wrote. "They had to evacuate the area and disarm the device."
Two Army Special Forces soldiers told investigators that they suspected the explosives were placed by a Syrian contract employee or an SDF member, possibly having been paid to do so by the Islamic State or a militia backed by Iran, Russia or the Syrian government.
While the U.S.-SDF relationship had been largely positive, witnesses told investigators that they suspected their Syrian liaisons had been stealing equipment, too.
There was also an altercation weeks before the explosions, after a person whose name and nationality was redacted used the Arabic phrase "Inshallah," meaning "if God wills," in a way that offended some SDF members, an investigator wrote. Other "rude" comments "led to a further conflict," and a person whose name and nationality was redacted was removed from Green Village because of "safety concerns," the investigator added.
Wladimir van Wilgenburg, an analyst based in Iraqi Kurdistan, said attacks against Americans by the predominantly Kurdish SDF have been exceptionally rare. He knew of only one instance: An SDF fighter shot an American in 2018 for reasons U.S. officials said were unclear.
"It is not like in Afghanistan where local police attacked U.S. soldiers," van Wilgenburg said. "The SDF needs the U.S. to stay in northeast Syria, otherwise the Syrian government or Turkey will attack."
Western intelligence reports cited in the investigation warned that, while local adversaries may have possessed the ability to carry out an attack like the one at Green Village, no one had claimed responsibility for having done so. Officials said that was unusual.
A Special Forces soldier told investigators that it seemed like intelligence officials sought to "steer" the probe away from scrutinizing the SDF and suggested that they examine the sources of those reports. Spokespeople for the Army and Air Force investigative agencies declined to say whether that was done.
The specter of U.S. adversaries co-opting foreign workers or militiamen was bound to raise doubt among a military jury in the United States, according to Franklin D. Rosenblatt, a former Army attorney who teaches at the Mississippi College School of Law.
"Regardless of whether there is any merit to those concerns," he said, "they were likely top of mind when deciding this whodunit."
