Man hit, killed by Frontier Airlines plane at Denver International Airport had lengthy criminal history

Federal investigators and Denver police are continuing to piece together what led up to a deadly runway incident at Denver International Airport in which a trespasser was struck and killed by a departing Frontier Airlines plane.

Authorities say 41-year-old Michael Mott died after Frontier Flight 4345 struck him around 11:15 p.m. on Friday while the aircraft was taking off.

Airport officials say the incident quickly became a massive emergency response and crime scene investigation.

"We knew this was going to be considered a crime scene, which is why we went through great pains to make sure we had people in certain areas and bus them back to the terminal," Denver International Airport CEO Phil Washington said during a press conference.

Investigators say debris from the incident was spread across nearly 4,000 feet in the area.

The Denver Office of the Medical Examiner determined Mott died from multiple blunt and sharp force injuries. His manner of death was ruled a suicide.

"I want to take a moment to acknowledge the news of this nature can be very painful for the family, witnesses and any members of our community," Chief Medical Examiner Sterling McLaren said.

Investigators say Mott climbed over an 8-foot fence topped with barbed wire before entering the restricted airfield. Officials say he walked in front of the plane about two minutes later.

Court records show Mott had a lengthy criminal history across multiple Colorado counties, including Pueblo, Montezuma and El Paso. Records show arrests over the years involving violent offenses, including attempted murder charges.

Denver police say investigators are still trying to learn more about Mott's motives.

"As we speak, investigators are out contacting family and others who knew him to see if there are additional information that we can learn about his motivation," Denver Police Chief Ron Thomas said.

Chief Thomas also acknowledged the emotional toll the incident has had on passengers, witnesses and first responders.

"This was an incredibly difficult and traumatic situation for a lot of people, and my heart goes out to all of them as they process what they experienced," he said.

Denver police are asking anyone with information about Mott to come forward. Officials say his last known address was in Pueblo.