A man and woman are dead and a Gwinnett County police officer is on administrative leave after gunfire broke out early Wednesday during a domestic incident near Buford.

Officers responded to the domestic dispute call at a home in the 6400 block of Old Shadburn Road shortly after 12:30 a.m., Gwinnett police said in a statement.

An officer was approaching the home when he saw Betty Jo Massengale, 80, walking toward him in the driveway, police said.

As she approached the officer, Massengale was shot in the back by the 73-year-old James Daniel Guler, and fell to the ground, and the officer returned fire at Guler.

Guler fell to the ground and fired another shot, according to police.

Both Massengale and Guler died at the scene, but police had not determined whether the Guler died from the officer’s shot or from a self-inflicted gunshot.

“We’re not sure at this point,” Gwinnett police Sgt. Brian Doan said. “We’re not sure if the officer struck the male with his rounds.”

The officer was not injured, but was placed on routine administrative leave. His name has not been released.

Gwinnett police Cpl. Michele Pihera said late Wednesday morning that Massengale and Guler both lived in the home, but were not married.

Pihera said there is no history of domestic-related matters involving the two within the past several years.