11:47 AM PT -- Colt Gray is being charged with four counts of murder, according to a statement from the Georgia Bureau of Investigation.

New video from the aftermath of the deadly school shooting at a Georgia high school shows the heroism of the teachers and staff ... with a woman tending to one of the gunshot victims.

In the footage, obtained by TMZ, you see a body lying face-down on the floor and bleeding out ... with a woman, presumably a teacher, trying to stop the bleeding with rags and towels.

There's a ton of blood around the victim, who is down in one corner of the classroom ... chairs are knocked over and desks are askew ... indicating chaos and panic after shots rang out.

Despite the traumatic deadly shooting, it looks like school staff were quick to jump in and help before police and emergency workers arrived on the scene ... and in the video, someone comes over to the woman and offers her another rag to use to stop the bleeding.

Wednesday's shooting at Apalachee High School in Winder killed four ... including 14-year-old students Mason Schermerhorn and Christian Angulo, plus teachers Christina Irimie and Richard Aspinwall ... making it the deadliest school shooting in Georgia history.

Nine others were taken to hospitals with injuries ... and fortunately, they are all expected to survive.

The Georgia Bureau of Investigation says the shooting suspect has been identified as Colt Gray, a 14-year-old male student at the school. Officials say Gray will be charged with murder and prosecuted as an adult, and he used an "AR-platform-style weapon."