Police said the two have children together and share a home.
The fatal shooting was one of at least three in DeKalb County over the weekend.
On Friday, 18-year-old Taneaious McCune was shot along with three other people while trying to break into a home on Gresham Road, police said. McCune later died at a hospital. The surviving suspects were all charged with felony murder for their involvement.
ExploreCandlelight vigil for teen shooting victim in DeKalb turns deadlyDuring a vigil Sunday evening for McCune at the Highlands at East Atlanta complex, 17-year-old Ian Hagerty was killed and two other boys were injured when someone began shooting, police said. Authorities have not said how the three victims are connected to McCune.
On Saturday, Janautica Whitehead, 19, was found dead inside a vehicle along Snapfinger Parkway, police said. No other details were released about the shooting.