CNN
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The man who blew up a Tesla Cybertruck outside the Trump International Hotel in Las Vegas wrote about “political grievances,” armed conflict elsewhere and domestic political problems in the days before his suicide, officials said Friday.

The writings were found in the cellphone of Matthew Alan Livelsberger, the truck’s driver, Sheriff Dori Koren of the Las Vegas Metropolitan Police Department said in a news conference.

In his writings, the driver of the Cybertruck said the incident was not intended as a “terrorist attack” but rather as a “wake-up call,” according to police. In a letter seized by investigators, he wrote that “Americans only care about spectacle and violence” and that “fireworks and explosives” were the best way to make his point.

Livelsberger wrote that he needed to “cleanse” his mind of the “brothers I have lost” and free himself of “the burden of the lives I have taken.” He said the US was “terminally ill and on the way to collapse.”

The Cybertruck was detonated outside a Trump International Hotel in Las Vegas on Wednesday. Livelsberger, 37, of Colorado, died in the incident and seven others were injured. Authorities said Friday his identity had been confirmed.

Spencer Evans, special agent in charge of the FBI’s Las Vegas division, said the incident appeared to be “a tragic case of suicide involving a decorated combat veteran who was struggling with post-traumatic stress disorder and other issues.”

Evans said that “other family issues or personal grievances in his own life … may have been factors” in the man’s actions. “It is obvious that the subject alone thought, planned and carefully prepared this act,” he added.

Investigators said they were still combing through “a lot of content” related to the case, including two cellphones, and determined there was no connection between Livelsberger and the New Orleans attack.

Livelsberger, an active-duty Green Beret in the US Army, was on leave from his base in Germany at the time of the explosion, sources told CNN. The explosion was caused by a combination of fireworks, gasoline tanks and camping fuel in the bed of the vehicle, ignited by a driver-controlled device.

In a 10-day “activity journal” or “monitoring log” kept on one of his phones from Dec. 21 to Dec. 31, investigators reported that Livelsberger recorded his purchases of firearms, camping equipment and other items.

Editor’s note: Help is available if you or someone you know is struggling with suicidal thoughts or mental health issues. In the US: Call or text 988 Suicide and crisis lifeline. Worldwide: The International Association for Suicide Prevention And Friends worldwide have contact information for crisis centers around the world.