Austin Thompson's former teachers testify: 'How did this ever happen?'

RALEIGH, N.C. (WTVD) -- Austin Thompson's defense team called several of his former teachers to the stand, most expressed their shock he was responsible for the attack.

English teacher Chelsea Mulholland taught Thompson in class before the mass shooting.

The next morning, she testified a department head pulled her aside and notified her Thompson was responsible for killing five people.

"At first, it's like shock and awe. How did this ever happen," said Mulholland. "The likelihood of knowing someone who had done something newsworthy like that just is not it's not believable. It's just surprising and shocking."

Former art teacher Neal Gallagher said Thomspon would draw weapons in a sketch book, but that was normal for kids his age and that Thompson did not sketch acts of violence.

"All three years, he was not a problem child. He was very quiet," he said.

Thompson has been serving time since the mass shooting at Cumberland Juvenile Detention Center.

Darcy Ross is a Behavioral Specialist there.

She said Thompson has been granted privileges such as watching movies and playing video games.

Ross says at times, he does try to push the line with staff.

"Sometimes, he'd get really upset and he'd mumble under his breath. You can't really hear what he's saying, but we redirect that," said Ross.

Thompson finished his high school education while in custody and a ceremony was held solely for him to mark the achievement.

SEE ALSO: Follow our live updates for the Austin Thompson sentencing