Transcript for Alleged Santa Fe HS shooter charged with capital murder
On this Saturday night, we are here in Texas at the scene of the latest mass shooting at an American school. Tonight an entire campus wrapped in police tape. This one taking the lives of ten people, eight of them students. A gunman in a trench coat opening fire early yesterday morning. Students Seng. First responders rushing in. Two police officers confronting that shooter. The suspect, a 17-year-old student, surrendered and allegedly confessed to the crime. He already appeared before a judge and is now charged with murder. Tonight a portrait of the gunman is coming into focus, and we're getting what it was like to be inside that terrifying attack. Tonight, the injury count rising in that deadly school shooting. In Santa fe, Texas, police say ten people were killed, most of them students. And now 13 are recovering from injuries including gunshot wounds. Are you a citizen of the United States? Yes, sir. Are you requesting consideration for a court appointed attorney? Yes, sir. Reporter: The alleged teenage killer facing a judge charged with capital murder and being held in solitary confinement. Tonight he's on suicide watch. He is in a place where I'm not sure what he understands. Reporter: Lawyers for the alleged killer, 17-year-old dimitrios pagourtzis, have now met with him twice. Police say the teenage shooter took a shotgun and a pistol that belonged to his father. His lawyers say the guns were locked in a gun cabinet. The parent has no idea of their son's alleged plan. They didn't know, they didn't expect and couldn't have predicted. He's actually shooting. He's in the art room. We've got shots fired. Reporter: Students tell ABC the alleged shooter came through the back of the school and authorities say he was carrying explosive devices that did not function. Sophomore Rome Schubert was inside the first classroom targeted and said the shooter first tossed in one of those homemade bombs. He threw something at the desks and I heard it but didn't think nothing of it. Just sounded like a pin. Five seconds later a loud bang. My ears started rings, a laud bang, a loud bang and then everything kind of went crazy from there. Reporter: Schubert, a star pitcher on the school's baseball team, says he barricaded himself behind a desk before running for safety not knowing he had been shot in the head. Luckily, the bullet exiting with minimal damage. I had no idea till I looked at my shirt and there was blood live came up behind me and dripping down and then my friend said you got shot in the back of the head. Reporter: Students say they remember hearing a fire alarm going off alerting them of danger. Students running out of their classrooms to hear gunshots and see their classmates wounded and dying on the floor. We were playing dead. Reporter: Police and S.W.A.T. Teams surrounding the school. Kids lining up on the field emptying their backpacks for officers to inspect. Their hands on their heads. I didn't know what to think. I shouldn't be going through this. It's my school. This is my daily life. I shouldn't have to feel like that. I feel scared to even go back. Reporter: Students we spoke with say the gunman was quiet and odd but not violent. He'd wear the trench coat always? Every day. Every single day. Even if it was 90 degrees outside. Every single day. Reporter: Investigators have not said what set the teen off. According to the probable cause affidavit, the suspect surrendered allegedly telling police he did not shoot students he did like so he could have his story told.
This transcript has been automatically generated and may not be 100% accurate.