Military personnel manning a U.S. Army command outpost in Iraq found the radio report suspicious. During an operation to hunt suspected al-Qaeda militants, American soldiers involved notified their commanders that they had just killed three detainees whom, they said, had broken free of their restraints and attacked them.

The soldiers had been in combat for months in Samarra, a city about 80 miles northwest of Baghdad, where a vicious insurgency had taken hold. The detainees' deaths on May 9, 2006, triggered an extensive U.S. military investigation, leading to courts-martial, two murder convictions, and a career-ending letter of reprimand for Col. Michael Steele, the troops' brigade commander. In the end, those found guilty acknowledged under oath that they had lied about the detainees' escape, and instead set them loose and shot them in the back as they ran away.

"Every single person that was involved in that has had an indelible mark left on them," Steele told the Washington Post in an interview. He attributed the murders to "guys that decided to go rogue."

The cases have taken on new significance with President-elect Donald Trump's nomination of Pete Hegseth for defense secretary. Hegseth was a 26-year-old lieutenant in the Army National Guard when he joined that unit, the 101st Airborne Division's 3rd Brigade Combat Team, in summer 2005 just ahead of its deployment. Though he was not present during the murders and had no role in them, the incident was formative, other soldiers said, with men he grew to care about ensnared in the case.

This account of Hegseth's deployment to Iraq is based on interviews with eight people familiar with that time in his life, along with a review of military documents and past media accounts. Taken together, a picture emerges of a potential secretary of defense who witnessed an extended inquiry into military misconduct that upended the lives of colleagues and mentors. The experience left soldiers not directly involved in the murders convinced that the Army had turned on them, too, those involved said.

Hegseth and representatives for the Trump transition team did not respond to requests for comment. Some people spoke on the condition of anonymity to discuss a high-profile potential nomination that is embroiled in controversy for other reasons. In recent days, the Post and other news organizations have revealed that Hegseth was investigated by police in 2017 for an alleged sexual assault. His lawyer, Timothy Parlatore, has said that the encounter was consensual and that Hegseth was not charged with the crime, though he later paid to settle the matter with the accuser.

Hegseth, 44, has rarely, if ever, mentioned the Iraq cases publicly, and has shifted in the years since from being an ardent supporter of the 2007 surge of U.S. forces in Iraq to questioning the entire point of the war. Over time, he also took on an increasingly populist tone in defense of U.S. troops accused of war crimes, arguing that the military put unreasonable restrictions on the rules of engagement that govern how American soldiers fight.

His appearances on the cable news show "Fox & Friends Weekend" captured the attention of then-President Donald Trump, leading to phone calls between them, people familiar with the matter said. Hegseth took particular interest in three prosecutions: those of Army officers Clint Lorance and Mathew Golsteyn for alleged murders in Afghanistan, and Navy SEAL Edward Gallagher, who beat a murder charge but was punished for staging a photo with an Islamic State fighter's corpse in Iraq.

In November 2019, after Trump pardoned Lorance and Golsteyn, and reinstated Gallagher's rank — rejecting pushback from senior Pentagon officials — Hegseth gave a full-throated defense of the moves, telling Fox viewers the president had shown support for "people out there making the impossible calls at impossible moments."

"These are not cases where people went into villages with the intention of killing innocent people," Hegseth said, dismissing evidence and testimony pointing to violations of military law. "These are split-second decisions."

Privately, Hegseth commiserated with Golsteyn about the investigation the 3rd Brigade Combat Team had endured, Golsteyn told the Post. It appeared that Hegseth saw "a replay of events in my case that were relatable to his own experiences," Golsteyn said.

Hegseth worked at Fox until recently, decamping the network this month when his nomination was announced.

'Kill Company'

Hegseth graduated from Princeton University in 2003, joining the investment bank Bear Stearns and the Minnesota Army National Guard as an infantry officer. He deployed in 2004 first to Guantánamo Bay, the U.S. detention facility in Cuba that at the time housed hundreds of 9/11 suspects and combatants in the war on terrorism. After returning to Wall Street for a brief interlude, he volunteered for an assignment to Iraq in 2005, landing a slot as a platoon leader overseeing about 40 men in the brigade's Charlie Company, 3rd Battalion, 187th Infantry Regiment.

"I showed up in the 101st Airborne Division, in one of the most storied units in our nation's history, with a bunch of combat vets who'd already done a tour in Iraq and they looked at me like, 'Who the hell is this guy?'" Hegseth said in a 2021 interview on the "Will Cain Show" podcast.

One former officer who served with Hegseth said he was surprised to see a National Guard member taking on such a role. He surmised that Hegseth probably wanted to run for office someday and thought a combat tour could help, the former officer said.

On the battlefield, Hegseth appeared calm and levelheaded, two soldiers who served with him said. He led missions initially in Baghdad and then around Samarra, said retired Sgt. Maj. Eric Geressy, who served as the senior enlisted soldier in Charlie Company. The fighting became especially intense, Geressy recalled, after an important Shiite landmark, the Golden Mosque, was blown up in February 2006, triggering a wave of sectarian bloodshed with U.S. forces caught in the middle.

"The enemy really threw everything at us there," Geressy said. "Suicide bombers, mortars, rockets — anything and everything."

Charlie Company, numbering about 140 men, was considered the brigade's most aggressive unit, engaging threats with a bravado that would later draw scrutiny from senior leaders, said people familiar with the deployment. As recounted by the New Yorker in 2009, Charlie Company was nicknamed "Kill Company" and maintained a whiteboard listing confirmed kills — including civilians — that each platoon had notched.

The former officer, who served in another company within the battalion, said the behavior exhibited by Hegseth's infantry company was viewed as "a little bit strange" by those on the outside: "We joked sometimes that they were on their own crusade down there."

Hegseth, in an interview for the New Yorker article, said that Charlie Company's aggressiveness was shaped by training it had received while preparing for the deployment at Fort Campbell, Kentucky. He claimed then that he voiced concerns to his former company commander, Capt. Daniel Hart, that he didn't "feel comfortable telling my guys to go into that door hot," with their weapons poised to be fired.

"I can't quote him directly, but he said, 'What do you mean? This is an enemy target, we have intelligence that it is an Al Qaeda mortar team,'" Hegseth told the New Yorker. "And I said, 'I understand that, sir, and I don't want to put my platoon in danger, but at the same time I am talking to other people who have been here for a while and nobody else goes in hot — nobody. And if we go in hot we are going to kill civilians.'"

Hart, now an Army colonel and military psychiatrist, declined through an Army spokesman to comment on Hegseth's comments.

Hegseth eventually was reassigned and tasked with overseeing local governance projects in Samarra, where there had been little order since the region's decent into violence, Geressy said. Steele and Geressy both lauded his service in interviews with the Post.

But for his old unit, disaster was coming.

Operation Iron Triangle

Steele, the brigade commander, had survived the infamous "Black Hawk Down" incident that killed 18 U.S. soldiers in Somalia in 1993. He held a mindset that, in the run-up to their deployment, there was little time for anything other than preparing for war, several soldiers who served under him said. Once in Iraq, he clashed frequently with senior commanders over strategy and tactics, as U.S. forces struggled to simultaneously squelch the violence and win over the civilian populace, several people said.

After Hegseth's departure, as fighting in and around Samarra soared, Steele and his staff engineered a series of helicopter assaults intended to pummel the militant forces. One such mission, branded Operation Iron Triangle, targeted an al-Qaeda training facility on a tiny island in Lake Tharthar.

Charlie Company's 3rd Platoon lifted off in Black Hawk helicopters expecting a fierce battle, soldiers involved said. Their target, according to a military document describing the operation that was obtained by the Post, was "full of Al Qaeda" and associates of Abu Musab al-Zarqawi, the leader of al-Qaeda in Iraq, a precursor to the Islamic State.

Geressy, in a witness statement submitted after the operation as part of the inquiry, said that soldiers began clearing houses after their helicopters landed but that the first few houses had no one inside. Later, when soldiers were flown to another part of the island, they opened fire on a building, killing one man and taking several people captive, he told military investigators.

Geressy was elsewhere on the island at the time, he told investigators, and instructed the soldiers to prepare the detainees to be moved by aircraft for an intelligence screening by other Army personnel. About 20 minutes later, the captives were dead.

Hart, Hegseth's former superior officer, sent a memo to Steele saying the first man killed had looked through a window as the soldiers approached and that three other "military aged males" had used their wives inside the building to shield themselves. Hart's report also said that his soldiers used deadly force to respond to a hostile act by the detainees. A military court later determined that account to be false. An Army official familiar with the matter said that Hart wrote the report based on what he believed to be true at the time.

As the story fell apart, Army investigators alleged that two soldiers, Cpl. William Hunsaker and Pfc. Corey Clagett, shot the detainees and accused a more senior member of the unit, Staff Sgt. Raymond Girouard, of ordering the killings and then helping to cover them up. A fourth, Spec. Juston Graber, was accused of shooting one of the detainees in the head after the initial gunfire stopped to "ease his suffering," he told investigators.

Clagett and Hunsaker pleaded guilty to murder and related charges, receiving prison sentences of 18 years each. Graber pleaded guilty to aggravated assault, receiving a sentence of nine months in exchange for his testimony against the others, and Girouard was convicted of negligent homicide and other charges and sentenced to 10 years, according to military documents. Girouard's conviction was later overturned on appeal, while the others have since been released.

Clagett, Hunsaker and Girouard did not respond to requests for comment. Graber, now 39, said in a text message that he is writing a book about his experience, including carrying out "that mercy killing."

"War is complete and utter hell, and, unless you're there, on the receiving end of flying bullets or recovering your brothers … you'll never comprehend the complexities of what we go through nor the decisions we have to make," Graber's message said.

A unit under suspicion

Suspicion spread far beyond the soldiers eventually sent to prison. Defense attorneys for the men accused depicted a bloodthirsty and undisciplined culture within Hegseth's old infantry company. The experience, one senior soldier in the unit said, was searing for all of them.

Steele received the letter of reprimand from Lt. Gen. Peter W. Chiarelli, who later became a four-star general and vice chief of staff of the Army. In a phone interview, Steele said that Chiarelli "tried to connect the murder of the detainees to my command climate" and that others in the brigade thought the general's conclusions were "ludicrous."

Steele portrayed Chiarelli as disconnected from what rank-and-file infantry personnel experienced, saying the general "lived in a palace" in Iraq "while my guys are out bleeding to death in the streets of Samarra." His voice hardened as he recalled witnessing more senior commanders receiving orders to release militants who had been captured by U.S. forces.

"There are soldiers that absolutely died because of that stupidity," Steele said.

Asked about the Charlie Company's "kill board" and the harsh methods of training he instituted, Steele said he did not condone illegal behavior but wanted his soldiers not to be timid when their lives were in danger. Death, he said, is "irrevocable."

"I take it personally when somebody said, 'Well, I think your techniques are too hard,'" Steele said. "Well, you pick up a damn rifle and you go get in that fire team and you go out and you face insurgents with my guys, then."

Chiarelli said in an email that he reprimanded Steele "because the soldiers under his command violated the rules of engagement."

"I was in Iraq for one week, commanding the 1st Cavalry Division, when eight soldiers assigned to my division were killed and 64 were wounded in an ambush in Baghdad's Sadr City," Chiarelli said. "I understood and witnessed firsthand how violent a place it could be."

Steele said he supports Hegseth's potential nomination as defense secretary, calling his mindset a rarity for that job. Hegseth is intelligent, articulate, and will refocus the Pentagon on winning the nation's wars, the retired colonel said.

Critics of Hegseth's potential nomination have stressed that he has never led any large organization and has faced mounting scrutiny of his personal life and punditry, including advocating for firing generals who support diversity programs, opposing women serving in combat units and suggesting in a book that Islam "is not a religion of peace, and it never has been." He also has tattoos that were flagged by National Guard colleagues as being associated with the far right.

If he is formally nominated by Trump after his inauguration, Hegseth's confirmation will require a Senate majority vote — an assessment by lawmakers of whether he is ready to lead an enterprise that includes more than 3 million military and civilian personnel, a global network of installations, and nuclear weapons.

The former Army officer who served with Hegseth in Iraq said he believes he has latched on to "populist scenarios" in a quest for personal gain. When news of Hegseth's nomination emerged, old acquaintances from those days got back in touch with one another, the former officer said.

One text he received especially stood out. All it said: "WTF?"

Monika Mathur, Razzan Nakhlawi and Lisa Rein contributed to this report.