(CNN)A gunman killed at least four people, including a 7-year-old, and wounded two others Saturday afternoon at a home in suburban Atlanta, authorities said. The shooter, whose identity has not been released, shot six people before he shot and killed himself, said Douglas County Coroner Randy Daniel. The 7-year-old, two adults and another minor were killed. Two children sustained life-threatening injuries. Daniel told CNN that investigators were "still trying to sort this out" when asked whether the gunman and his victims were related. Sheriff's Chief Deputy Stan Copeland told CNN affiliate WSB-TV that in his 38 years on the job "(he'd) never seen this many victims in one shooting." "Neighbors are in shock," he said. Douglas County is west of Atlanta.
Shooter kills 4, wounds two, before killing himself at a home outside of Atlanta . Two minors who survived sustain life-threatening injuries .