Deputies responding to multiple calls shortly after 1 am found two bodies in the driveway and one in the doorway of a house on Crabapple Court, the county sheriff's office said.
As deputies arrived, a fourth person ran into the residence, after which a gunshot rang out, the Coweta County Sheriff's Office said in a post on X.
A SWAT team secured the area, and police later found the body of the fourth person in the home, the sheriff's office said. The office is investigating the incident as a murder-suicide.
The identities of the deceased were not immediately released, pending notification of their families, NBC news reported.
The Coweta Sheriff's Office said it would provide more information as the investigation unfolds.