Update, 5:09 p.m. According to WSB reporter Jovita Moore, the gunman allegedly ordered the school to call the news channel because he wanted news cameras to "film as police die." Something changed inside him once the U.S. Marshals and other law enforcement showed up, though. He surrendered peacefully after a brief exchange of fire. 

Update, 2:35 p.m. WSB-TV has the first information on the shooter and what type of weapon used: 

Channel 2 Action News has confirmed with multiple sources that the suspect is a white man in his 20s who was armed with an AK-47 and dressed in black. Sources say he surrendered peacefully.

Update, 1:53 p.m. WSB-TV and NBC's 11 Alive affiliate report no children were injured in the shooting. The suspect's motive is the biggest mystery right now. 11 Alive reports the suspect had "demands," without elaborating on those demands. WSB-TV reports they first heard about the shooting because the suspect demanded a woman in the school office call the channel: 

A woman in the school office called Channel 2 Action News to report that there was a shooter in the school. She told a Channel 2 assignment desk editor that the gunman asked her to call WSB-TV. Shots could be heard over the call.

Original: A gunman opened fire inside an Atlanta charter school Tuesday, according to multiple local reports.

CBS Atlanta reports Dekalb County police were evacuating students from Ronald E McNair Discover Learning Academy Elementary School after a gunman opened fire inside the school. The Associated Press reports the suspect is now in custody. Strangely, WSB-TV reports the gunman demanded officials call WSB-TV once he entered the school. 

Children were evacuated onto the school grounds during the shooting. There are no reported injuries at this time. We'll update this post once we know more.