Four people were killed at a Georgia high school on Wednesday when a 14-year-old opened fire. The suspect, named as Colt Gray, a pupil, was arrested by two officers on the school campus and was in custody, a spokesman said. He will be charged with murder as an adult.

Video shows children evacuating the school and being reunited with their parents. Pupils who were at the school at the time of the shooting say they saw the boy pull out a “big gun” before starting to shoot.

Officials say at least nine people were injured in the shooting.