Police: Cybertruck driver used ChatGPT to plan Las Vegas explosion

The man responsible for exploding a Tesla Cybertruck outside the Trump International hotel used ChatGPT to help plan his attack, police said Tuesday.

Authorities also said for the first time that the Jan. 1 explosion could have been much worse.

A Bureau of Alcohol, Tobacco, Firearms and Explosives official said Tuesday that 70 pounds of birdshot were put inside the Cybertruck in addition to at least 60 pounds of explosive material including camp fuel and consumer fireworks.

“So we do know, as a matter of fact, the result of this explosion could be much greater,” said Kenny Cooper, assistant special agent in charge at the San Francisco Field Division of the ATF.

The disclosure came during a press conference Tuesday during which authorities said U.S. Army Master Sgt. Matthew Livelsberger had asked ChatGPT a series of questions about how to acquire and use explosive materials.

He made the queries on Dec. 27, the day before he rented the Cybertruck in Denver and began his journey to Las Vegas.

On the morning of Jan. 1, the 37-year-old active duty soldier fatally shot himself in the head an instant before his rented Cybertruck exploded, injuring seven bystanders.

A six-page manifesto left behind by Livelsberger showed he believed he was being followed, according to investigators. Sheriff Kevin McMahill said Livelsberger had no criminal history and was not on the Metropolitan Police Department’s or the FBI’s radar.

The day before Livelsberger arrived in Las Vegas, he wrote in his electronic journal that he was heading to the Grand Canyon. “I am going to make this as public as possible,” he wrote in an excerpt released by police. “I’m headed for the canyon.”

“There was a change in plans, and he showed up here,” Metro Assistant Sheriff Dori Koren said, adding that authorities do not yet know why he changed course.

The explosion

Among the questions Livelsberger asked ChatGPT were “What is the legal limit to buy Tannerite in Colorado” and “What pistol could set it off.”

Tannerite is a brand of reactive rifle targets that, if shot, explode. According to Koren, authorities were able to confirm that Livelsberger purchased exploding targets.

The use of ChatGPT in Livelsberger’s plans was a “concerning moment,” according to McMahill. “This is the first incident that I’m aware of on U.S. soil where ChatGPT is utilized to help an individual build a particular device.”

“It’s instructive to us,” McMahill said. He added that he doesn’t think that it would have been possible for Livelsberger’s ChatGPT searches to have raised any flags.

But while officials are still trying to determine how it was ignited, a fire seen flaring inside the Cybertruck outside Trump International hotel was a fuel-air explosion that was less powerful than what could have happened if Livelsberger had detonated high explosives, especially with the 70 pounds of birdshot in the truck that could have turned into high-velocity shrapnel.

The consumer fireworks in the truck were manufactured to ensure a mass of them could explode simultaneously, despite the fuel-air explosion, according to Cooper.

The evidence suggests “a large portion of almost 20 gallons of fuel were poured over the fireworks and explosive materials that were inside the cargo compartments of the Cybertruck,” Cooper said. Video in the press conference showed fuel leaking out of the vehicle and dripping on the pavement as Livelsberger drove into the hotel’s valet area.

Police said Livelsberger wrote that he had “no intent on taking out anyone but myself” and that he was “deeply sorry to anyone that gets hurt,” but Cooper said that it’s not clear whether Livelsberger backtracked from detonating the more explosive materials or that the fuel-air explosion he ignited failed to detonate them.

“We can’t get inside his head to answer,” Cooper said.

Livelsberger’s mental status

Authorities have said Livelsberger likely suffered from post-traumatic stress disorder and that he kept a diary on his phone leading up to the explosion.

“Consider this last sunset of ‘24 and my actions the end of our sickness and a new chapter of health for our people,” Livelsberger wrote, according to copies of the notes shared by the Metropolitan Police Department. “Rally around the Trump, Musk, Kennedy, and ride this wave to the highest hegemony for all Americans!”

Alicia Arritt, Livelsberger’s former girlfriend, told multiple news outlets that he confided in her about pain and exhaustion, symptoms that Arritt, who served as an Army nurse, said are typical of traumatic brain injury.

These kinds of injuries can cause personality changes later in life, Arritt told news outlets.

After losing contact for years, Arritt said that she received messages from Livelsberger in December, including videos of the Cybertruck and its dancing headlights, which can sync up with music.

Arritt told news outlets that she doesn’t know what drove Livelsberger to do what he did, but that she believed he needed more support from the military.

Authorities said on Friday that their investigation hinted at a possible motive, highlighting “potential other family issues or personal grievances” held by Livelsberger, in addition to his likely PTSD.

In an excerpt of the manifesto, Livelsberger wrote, “There was not a time during my two years in Afghanistan where I had a clear understanding or rational feeling in my heart of why my brothers were fighting and dying.”

“These graphic encounters replay in my head every day, all day and it has ruined my relationships with my family and friends. I am now a shell of a human being with nothing to live for,” Livelsberger wrote. He added that as he wrote, he was “super high on weed and drinking,” a fact that officials said they are still in the process of verifying.

McMahill said that officials still need to search a laptop, mobile phone and smartwatch owned by Livelsberger.

“This investigation is far from over,” the sheriff said.

If you’re thinking about suicide, or are worried about a friend or loved one, help is available 24/7 by calling or texting the Lifeline network at 988. Live chat is available at 988lifeline.org.

Contact Estelle Atkinson at eatkinson@reviewjournal.com. Follow @estelleatkinson.bsky.social on Bluesky and @estellelilym on X.