The man, suspected of killing his girlfriend days earlier, killed himself inside that plane.

The video shows the out-of-control regional jet racing through the St. George Municipal Airport.

The plane can be seen hitting a building, taking down fences and light poles, and ending up on top of cars in the parking lot.

9NEWS aviation expert, and former NTSB senior safety investigator, Greg Feith says the video could lead to security changes at regional airports.

"When you first see it, it is kind of awe inspiring," Feith said.

Sometime after midnight on July 17, the video shows a man running across the runway, jumping in a jet, and going on a destructive ride.

"He went through a fence, he hit a light pole," Feith said.

Feith says it looks like the pilot tried stealing the 50-passenger plane, but couldn't take off when he clipped part of the wing.

"This pilot had intent to either do physical harm to himself, which he did, or other people. Fortunately it was only buildings and cars," Feith said.

The Salt Lake Tribune obtained pictures from the City of Saint George, in which you can see the plane in the parking lot piled on top of cars.

Fourteen cars were damaged, the newspaper reported. Inside the plane, police say Brian Hedglin shot himself in the head.

Hedglin was wanted for murder in Colorado Springs. Police say he stabbed his ex-girlfriend Christina Cornejo. Court records show she had a restraining order against him.

"Looking at that video where the airplane comes zooming past the first camera, he's moving at a pretty good clip," Feith said.

Hedglin was a pilot for SkyWest airlines, a regional carrier which is headquartered at St. George Municipal Airport.

Hedglin's key card was deactivated when police named him a murder suspect.

"He scaled the fence, jumped over, got into the secure area," Feith said.

Feith says it's not uncommon for pilots to leave planes unlocked, especially at smaller airports like this, but getting into secure area takes inside knowledge and determination.

"For the flying public, it's not like they should be fearful that this is going to happen on a daily basis," Feith said.

The TSA, NTSB, and FAA are now investigating the actions of this rouge pilot, which could affect airport security everywhere.

"I think the lessons will be learned from the investigation by the Federal authorities," Feith said.

St. George police and federal investigators are looking at toxicology reports and the cockpit voice recorder to see if drugs or alcohol played a role in this.

The federal investigation continues into exactly how this happened and why.