The active duty US special forces soldier who blew up a Cybertruck in front of a Las Vegas hotel on New Year’s Day used ChatGPT to plan his attack.

Las Vegas Metropolitan Police Sheriff Kevin McMahill said the use of generative artificial intelligence to “help plan” the attack was a “concerning moment” and a “game changer,” ABC News reported.

A spokesperson for ChatGPT developer Open AI said the company is “saddened by this incident and committed to seeing AI tools used responsibly,” but did not say how that would happen.

The spokesperson said that their generative AI answered Matthew Livelsberger’s questions about building bombs with “public available” information and “provided warnings against harmful or illegal actvities.”

Las Vegas Assistant Sheriff Dori Koren said on Tuesday that Livelsberger used ChatGPT “to figure out the amount of explosives needed in order to conduct the explosion he was looking to cause.”

He also used it to find vendors to buy the fireworks he loaded in the back of the rented truck and asked whether a bullet fired by his gun “would ignite the explosives.”

Livelsberger loaded the back of the truck with more than 60 pounds of pyrotechnics and explosive material and poured 20 gallons of flammable fuel over them, Kenny Cooper, assistant special agent in charge of the Bureau of Alcohol, Tobacco, Firearms and Explosives’ San Francisco field division, said.

Investigators don’t yet know how the blast was ignited, but believe that the muzzle flash from Livelsberger’s suicide could have done the job.

The 37-year-old shot himself in the head before the explosion. Additionally, police released new video showing Livelsberger pouring what investigators say is racing fuel over the explosives in the back of the truck.

Koren also said that investigators have found a six-page document in another one of the phones found in the truck, along with the two “notes” blaming a host of his perceived ills on Democrats in government and calling for the US military to take over the city “until the purge is complete.”

Police are not releasing the latest document, which contains  a “variance of grievances and a constant evolution of his plans or intents of what he wanted to do,” because, they said, some of the information may be classified.

But, Koren said, Livelberger again criticized the Biden administration and talked about his memories of time in battle during two deployments in Afghanistan.

Koren insisted that he said he had no intentions of killing anyone other than himself in his terrorist attack and worried about being labeled a terrorist. Seven other people were wounded in the blast, which he carried out directly in front of the Trump International Hotel.

A US military official also confirmed that Livelsberger had been receiving mental health treatment over the past year. He was on leave from an assignment in Germany at the time of the blast.

Officials have said there is no direct connection between him and the truck killer in New Orleans a few hours prior to the Las Vegas blast, Fox News reported. Shamsud-Din Jabbar was an American-born former soldier but did not serve in the same unit as Livelsberger. Both served for a time at Fort Bragg, now Fort Liberty, but not at the same time. Police killed Jabbar in a shootout after he killed 14 people and injured 35 on a crowded Bourbon Street.