Watch Live: GBI briefing on Apalachee High School shooting

The Georgia Bureau of Investigation will hold a press briefing at 4:30 p.m. Wednesday on a Barrow County high school shooting.

The GBI confirmed earlier Wednesday a shooter killed four people and injured at least nine. There is a suspect in custody, though it was not immediately clear if the shooter was a student at Apalachee High School in Winder, Georgia, outside of Atlanta.

Prior to Wednesday’s shooting, there had been 29 mass killings in the U.S. so far this year, according to a database maintained by The Associated Press and USA Today in partnership with Northeastern University.