A junior at Apalachee High School who was sat next to shooting suspect Colt Gray revealed the alleged gunman's chilling behavior moments before he opened fire - and how she and her classmates narrowly avoided death. 

Lyela Sayarath said she was sat next to the 14-year-old in algebra class on Wednesday morning, and had no indication of the horror that would unfold as she described him as a 'quiet' teen. 

'He never really talked, he wasn't (in school) most times, he would just skip class,' she told CNN. 'Even when he would have talked, it was one word answers.' 

Sayarath said she 'wasn't surprised' when Gray was identified as the shooter, and said that 'when you think of shooters and the way they act, it's usually the quiet kid and he was the one that fit that description.' 

She said on the morning of the shooting, Grey excused himself from the room minutes before shots rang out, but when he left she assumed he was merely skipping class again. 

Sayarath said Gray left the classroom at 9:45am, around half an hour before active shooter alerts sounded, and thought he was skipping class as he didn't take a bathroom pass from their teacher. 

But while he was gone, a loudspeaker announcement told teachers to check their emails, before Sayarath said Gray re-appeared at their classroom door. 

Still not realizing the danger, Sayarath said a student went to open the door for Gray before jumping back at the sight of his gun.

'I guess he saw we weren’t going to let him in. And I guess the classroom next to me, their door was open so I think he just started shooting in the classroom,' she said.

She said he proceeded to fire off a number of bullets 'one after another', adding: 'When we heard it, most people just dropped to the floor and like kind of crawled in an area like piled on top of each other.'

Sayarath said her friend was in the next classroom and witnessed someone being shot, which left him 'shaken up'. 'He saw somebody get shot. He had blood on him. He was kinda limping. He looked horrified,' she added.

It comes as 14-year-old Mason Schermerhorn became the first of the four victims in the school shooting to be identified. 

The victim's family told Channel 12 News that Schermerhorn, an autistic student, was shot dead in the tragedy on Wednesday morning. 

Gray, 14, injured at least nine others in the horror shooting in Winder, Georgia. Barrow County Sheriff Jud Smith said Gray immediately surrendered when confronted by law enforcement, and 'gave up and got on the ground.'

Officials have not yet offered any identification on the other three individuals that were shot dead, and said there is no early indication that they were targeted specifically, although the investigation is ongoing.

It is unclear how the 14-year-old gunman got ahold of the weapon that was used in the attack, and authorities have not yet said what kind of firearm was used.

Following his arrest, Gray will be charged with murder and will be tried as an adult, the Director of the Georgia Bureau of Investigation said.

According to law enforcement, Gray opened fire at approximately 10:23am, hitting at least 13 people as frantic scenes took over the school.

Images showed students streaming out onto the campus as terrified parents raced to find their children, with one mother describing the scene outside the school as pure 'chaos.'