LAS VEGAS () The central question now is why would Matthew Livelsberger rent the Cybertruck in Denver on Dec. 28 and drive 1,000 miles to Las Vegas? It’s a mystery to those investigating the explosion outside of the Trump International Hotel and those who knew him.

Authorities tracked Livelsberger’s movements through Tesla charging stations in Albuquerque on New Year’s Eve and Kingman, Arizona, in the early morning hours of Jan. 1.

With fuel canisters and large firework mortars in the back, the Cybertruck was parked for 17 seconds before it exploded, according to investigators.

“I’m comfortable calling it a suicide with the bombing that occurred immediately thereafter,” said Las Vegas Sheriff Kevin McMahill. “I’m not giving it any other labels.”

Spencer Evans, a special agent in charge of the FBI’s Las Vegas Division, said they’re still investigating a motive.

“Obviously, we’re always concerned in these sorts of events to ascertain what the motive is,” he said. “We understand that’s at the forefront of everyone’s thoughts. So looking into exactly what the motivation is remains our No. 1 priority.”

As federal authorities continue to investigate Livelsberger’s home in Colorado Springs, a neighbor tells he seemed a typical family man.

“His wife … we just started working out together at the gym, not intentionally, but just coincidentally,” said neighbor Keni Mac. “She just had a baby … a newborn. We didn’t see him as much as we saw her, but he is around. All I can say is that they’re a very normal family, and so it’s very strange to me that this would be the case.”

Livelsberger’s LinkedIn profile shows a decorated Army veteran in the Special Forces who enlisted at 18 and spent nearly two decades in the career.

The New York Post reports that his wife had recently left him over accusations of infidelity.

Livelsberger’s former girlfriend claims he sent her texts out of the blue.

“I rented a Cybertruck. I feel like Batman or Halo,” he texted one, according to The Denver Gazette. She said the texts from Livelsberger were playful and lighthearted. “I just want everyone to know that Matt was the kindest man I ever knew.”

Livelsberger’s former girlfriend said that his behavior changed after he returned from a tour in the Middle East and that he suffered from a traumatic brain injury five years ago.