The highly decorated soldier who exploded a Tesla Cybertruck outside the Trump hotel in Las Vegas used generative AI including ChatGPT to help plan the attack, Las Vegas police have said.

The updates on Tuesday come nearly a week after Matthew Livelsberger, 37, fatally shot himself just before the truck blew up.

A review of Livelsberger’s searches through ChatGPT indicate he was looking for information on explosive targets, the speed at which certain rounds of ammunition would travel and whether fireworks were legal in Arizona.

Livelsberger, an US Army Green Beret who deployed twice to Afghanistan and lived in Colorado Springs, Colorado, left notes saying the explosion was a stunt meant to be a “wake-up call ” for the nation’s troubles, officials said last week.

Fire crews work outside Trump International Hotel in Las Vegas after the fire and explosion of a Tesla Cybertruck in the valet area on January 1 (Sam Morris/Las Vegas Review-Journal via AP)

He left mobile phone notes saying he needed to “cleanse” his mind “of the brothers I’ve lost and relieve myself of the burden of the lives I took”.

The explosion caused minor injuries to seven people but virtually no damage to the Trump International Hotel. Authorities said that Livelsberger acted alone.

Livelsberger’s letters touched on political grievances, societal problems and domestic and international issues, including the war in Ukraine. He wrote that the US was “terminally ill and headed toward collapse”.

Investigators had been trying to determine if Livelsberger wanted to make a political point, given the Tesla and the hotel bearing the president-elect’s name.

Livelsberger harboured no ill will toward President-elect Donald Trump, law enforcement officials said. In one of the notes he left, he said the country needed to “rally around” him and Tesla boss Elon Musk.