New details this morning about how the gunman pulled off this spree and what may have motivated him. David wright is in los angeles. Good morning, david. Reporter: Good morning, george. Pretty much... See More
New details this morning about how the gunman pulled off this spree and what may have motivated him. David wright is in los angeles. Good morning, david. Reporter: Good morning, george. Pretty much back to normal at l.A.X. If you're traveling through here, you'll be hard pressed to find signs of the attack on friday. Moments before l.A.X. Erupted in panic and mayhem -- paul ciancia arrived like a normal passenger. His roommate dropped him off unaware ciancia had no ticket and apparently no plan of boarding a flight. According to the criminal complaint filed, he walked up to the tsa check point, pulled out a smith & wesson assault rifle and shot the tsa officer at point blank range multiple times. He rode up the escalator. He allegedly came back and shot hernandez again, killing him. As we know, this is is the first tsa employee killed in the line of duty. It's a significant event. Reporter: Two other tsa officers were wounded. James spear, and tony grigsby. The fourth victim, a teacher, brian ludmer, an eagle scout, made a tourniquet for his leg. He saw what he thought was a police officer. Two police officers dragd him out of a closet. They put brian on the wheelchair and ran him out of the terminal to an ambulance. Reporter: Ciancia made it all the way down the terminal before authorities shot him. Inside his bag, a hand-written note against the tsa. His former roommate said hi had no idea. A very nice guy. A little bit alone and introve introverted. He said he was going back to jersey. Making amends with his dad. Spending holidays with his Reporter: That is not the roommate that dropped him off at the airport. They had lunch just last week. As for paul ciancia, he's hospitalized at ucla medical center under 24-hour guard and heavily sedated. To a little holiday gift for drivers.
This transcript has been automatically generated and may not be 100% accurate.