The fourth victim in last Saturday evening's murders-suicide at Rock Spring - Chickamauga, Ga., police officer Charles "Chuck" Dunn - has died of his injuries.
Officer Dunn, 52, lived at Rock Spring.
Walker County Sheriff Steve Wilson earlier said Mr. Dunn was off duty and not in uniform at the time of the shooting incident.
Mr. Dunn was a longtime family friend of the victims, it was stated.
Sheriff Wilson said earlier that three people were dead and one was in critical condition at an area hospital after a domestic-related shooting.
He said deputies were dispatched to the Woodstation Road home at 7:10 p.m.
after the 911 Center received a distress call from one of the victims.
Upon arrival, deputies discovered three persons were deceased and one person was suffering life-threatening injuries.
Sheriff Wilson said the initial investigation reveals the shooter, Russell David Payne, 54, of Marietta, Ga., and his wife, Jacklyn D. Payne, 54, of the Woodstation Road residence were separated and living apart. Mrs. Payne was living with her father, Eugene "Jack" Denny, 79.
Investigators determined that Russell David Payne arrived at the residence by vehicle. He exited the vehicle and began firing multiple .223 caliber rounds into the rear of the residence.
As he moved about, he made entry into the residence, where he continued shooting. Payne died from a self-inflicted wound. Mrs. Payne and her father were both shot and killed.
A fourth person in the house, Officer Dunn, appeared to have engaged the shooter.