Not true, this happened outside the school.
I was just going by the article:
APS chief: Shooting victim could be out of hospital on Thursday
http://www.myfoxatlanta.com/story/20922511/aps-chief
“Atlanta Public Schools Superintendent Erroll Davis said he is hopeful the victim of Thursday's shooting outside of an Atlanta middle school would be released on Thursday.
A 14-year-old boy was shot in the back of the head on Thursday. He was said to be alert and conscious as he was transported to Grady Memorial Hospital.
Atlanta Police Chief George Turner said that the suspect in the shooting was disarmed and apprehended by a school resource officer. That officer was an armed off-duty Atlanta Police officer, Turner said.
Investigators said that the shooting was not random, and they believe that there had been some sort of altercation between the two students involved, Turner said.
A police spokesperson told FOX 5’s Justin Gray that the incident should be classified as a shooting at a school and not a school shooting.
Davis said that there are metal detectors at the school and that it was not known how the gun got past them...”
-- I didn't follow it on television, but the above article mentions that the Public Schools Superintendent Erroll Davis didn't know how he got the gun past the metal detectors. He may have not known all the details at the time.