As we bring you new Te tails emerging late tonight about a soldier became a mass shooter. David Muir has new clues about the gunman's mental health and stories of survivors who described what it was... See More
As we bring you new Te tails emerging late tonight about a soldier became a mass shooter. David Muir has new clues about the gunman's mental health and stories of survivors who described what it was like to be face to face with him. Once again, David is reporting from the scene at ft. Hood. David Muir. Reporter: Diane good evening. For the first time the detailed account from inside that room, those horrific moments when that army specialist opened fire. Tonight, a mother and father on their way to see their son, sergeant Jonathan Westbrook, shot four times. He survived. The eldest Westbrook driving from Mississippi, revealing how it played out. He was shot four times. Reporter: What did your son tell you about what he witnessed before the shooting? The soldier had come into his office and he'd had some words with my son's supervisor. And, he was asking for a form to execute a leave. Some leave time. And, they suggested he come back the next day and so, he left just as they had suggested that he leave. But, only to return with a weapon. A 45 caliber semiautomatic pistol. A handgun. And shot one person right in my son's presence. And then turned the gun on my son, shooting him four times. Twice in the arm, twice in the chest. And then, he commenced firing randomly and my son then took cover under the desk and tables. Reporter: He said Lopez then left that office and went on the base and kept firing. You described your son getting shot twice in the chest and two more times in the arm, your son is lucky tonight, to be alive? My son is a blessed human being. He is blessed. He was not shot from a very long distance. He was shot, you know, pretty close up. Reporter: I hear your son is doing okay? Yes, he's doing much, much better. Reporter: He said he'll never forget the seven hours not hearing from his son. When you heard about these shootings and you were able to get your son on the phone, what did you say to him? That I loved him. I am so happy that you are all right. Reporter: Tonight, for the first time, we're now hearing from his son. Next thing going through my head was my family, my wife and my children. Make sure I get safe so I can stay alive for them and that's what I did. And through the grace of god I came out of there alive. Reporter: Officials acknowledging that there was a verbal altercation before the shootings. When he was done firing, he covered an area as large as two city blocks. They're taking a look at his comb combat. Late today, they said they don't believe his mental health played a role in the shootings even though he had been prescription drugs and had seen a psychiatrist here. For the first time, Lopez's father back in Puerto ricoish sh issuing a statement. The complex where Lopez lived with his wife and 3-year-old daughter, authorities have now searched the apartment and talked to his wife. The mother of sergeant timothy Owens said she called her son the moment he heard about the shooting. I left a message on his phone to let me know if he's okay or not. And the fiancee, he was killed by the shooter. Emergency teams race to ft. Hood, that chaplain who saved lives was wounded himself while helping others, he was actually shielding them from more gunfire. Breaking windows to help them out. As a community prepares for a memorial service next week, a veteran, three crosses that he's placed in front of his church. A fellow killing a fellow soldier that's not the way it's supposed to be. That memorial service planned for next week, that wounded chaplain he's expected to be okay, Diane, one more note tonight about two other heroes, two wounded soldiers who bravely reached for their cell phones to call 911 even though that specialist was still firing. David, what you said about the large area in which with the gunman was firing. Thank you for leading us off again tonight.
This transcript has been automatically generated and may not be 100% accurate.