The active-duty U.S. soldier found dead in a Tesla Cybertruck that exploded outside the Trump International Hotel in Las Vegas once confided in an ex-girlfriend that he had suffered a traumatic brain injury while deployed overseas, she told The Washington Post.

Alicia Arritt, a 39-year-old nurse who has cared for wounded military veterans, dated Matthew Livelsberger on and off from 2018 to 2021.

During that time, she said, Livelsberger - who was on approved leave from his Special Forces unit in Germany at the time of his death - told her that he had struggled with a cloudy memory, poor concentration, difficulty maintaining relationships and intense guilt over his actions in combat.

Arritt recognized those symptoms as consistent with what can follow a blow to the head or massive jolt to the body. Such injuries, she knew, could fuel a gradual, heartbreaking deterioration of someone’s mental state. Several of her veteran friends and former patients, she said, have died by suicide.

“He wanted to get more help,” she recalled of their conversations. “I think it was even harder for him, being on active duty - the shame and the stigma.”

Livelsberger’s injury may help illuminate how the decorated 37-year-old Green Beret ended up dead in a Tesla Cybertruck that authorities say exploded after he fired a gun into his head while parked in front of Trump International Hotel in Las Vegas. The explosion came hours after an Army veteran from Texas drove a truck with an Islamic State flag into a crowd of New Year’s revelers in New Orleans, killing 14 people. The two incidents sparked alarm and fears of an orchestrated attack, but investigators said they have not found anything to suggest a connection.

The Las Vegas Metropolitan Police Department said late Thursday that Livelsberger’s death was an apparent suicide.

After meeting on Tinder in 2018, Arritt said she and Livelsberger began texting about his life in the military. Arritt had tended to veterans with brain injuries at Walter Reed National Military Medical Center and provided The Post with documentation of her employment there.

“Get hurt at all?” Arritt asked, according to the exchange she shared.

“Just some concussions,” he replied.

Later, she said, he revealed to her the long-term consequences. The restless nights. The trouble focusing. The frustration. Mounting evidence shows that repeated blast exposure throughout military service can damage the brain’s neural pathways, experts say. In severe cases, personalities are transformed. Struggles intensify. Lengthier combat stints elevate the threat of what the Pentagon calls “one of the invisible wounds of war.”

Livelsberger’s 18-year career, including numerous deployments to Afghanistan, put him at risk of prolonged exposure. He was awarded a Bronze Star with valor and an Army Commendation Medal with valor, the Army said - both of which honor courageous acts on the battlefield. His five Army Good Conduct medals indicate long periods of service free of disciplinary action.

Federal and local law enforcement officials declined to comment Friday on Arritt’s account of Livelsberger’s injuries and to what extent it may be a factor in their ongoing investigation of the explosion.

While they were dating, Arritt said, Livelsberger had also undergone back surgery to address pain he had been experiencing after jumping out of planes. Livelsberger was qualified in free-fall jumping, the Army said, an advanced parachuting skill common among special operators.

Arritt was shocked, she said, when FBI agents appeared at her door Thursday, inquiring about Livelsberger’s motive. The charred Cybertruck had contained what was left of his passport, military ID, credit cards and cellphone, which showed she was among the last people whom he texted.

“I rented a Tesla Cybertruck. It’s the s---,” he typed to her at 9 a.m. Sunday before sharing photos of the vehicle. They had kept in touch lightly over the years. Livelsberger had gotten married. Arritt said she was focused on raising her 15-year-old son in Pueblo, Colorado.

But she saw him as the “one who got away,” she said, and cared for him from what she envisioned as a respectful distance. They bonded, she thought, because she had been an Army nurse who could understand his pain. Livelsberger had told her that he had grown up with a loving family and close friends. After the brain injury, though, he said he’d grown more isolated.

She wasn’t sure how the injury happened, she said - just that he’d gotten the diagnosis at some point before they met in 2018. “He tried to put on a strong face,” she said. “Macho stuff.”

Arritt told the FBI agents that Livelsberger had suffered a brain injury, she said. She could think of no motive for why he would drive up to one of Donald Trump’s hotels with a vehicle full of fireworks and gas canisters. Before learning that he had shot himself inside the Cybertruck, Arritt’s first thought was: The Tesla must have randomly burst into flames.

The exes had also connected over a love of Teslas. She’d purchased a Model S from an auction, she said, and that car caught fire last year while charging.

The man she’d known hadn’t seemed like any sort of extremist, she said. Arritt described Livelsberger as “politically moderate” - though he leaned more conservative - “incredibly intelligent” and “never mean.” They’d broken up, she said, because he didn’t want to be a stepfather to her son and because she didn’t want to be moving around to accommodate his career.

“He was clear about what he wanted,” she said, “and was respectful about that.”

Livelsberger had been proud to serve his country, she said. He’d sent her photos of himself in camouflage fatigues, posing next to five long guns, according to images she shared with The Post. Another snapshot captured him grinning next to a muddy off-road vehicle.

previous coverage

• Driver in Tesla Cybertruck explosion was Green Beret based in Germany who likely died by self-inflicted gunshot

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