Police believe a husband fatally shot his wife before turning the gun on himself in Prince George's County. (WUSA9)

A Prince George’s County man fatally shot his wife Sunday before turning the gun on himself in an apparent murder-suicide, county police said.

On Monday, authorities identified the slain woman as Tonya Wilkerson-Sullivan, 35. Her husband was identified as Antoine Elvin Sullivan, 37.

Officers were called to the couple’s home in the 30 block of Joyceton Way, in the Kettering area, shortly after 10 a.m. to investigate a report of a shooting, police said. The couple were found suffering from gunshot wounds and pronounced dead at the scene, police said.

Detectives believe that the couple were arguing before the shooting, police said.

Sullivan was an employee with the D.C. Protective Services Division, the police force that patrols property owned, leased or otherwise controlled by the city government, according to Prince George’s officials. After a preliminary investigation, it appears that Sullivan used his service weapon to shoot himself and his wife, police said.

Wilkerson-Sullivan worked for the Prince George’s Department of Permitting, Inspections and Enforcement. A spokeswoman for the department said in a statement that Wilkerson-Sullivan “impressed her supervisors and was well liked by colleagues.”

“Although she had worked for the agency for just a short time, Tonya quickly became part of the DPIE family with her energetic willingness to learn and work,” said Susan Hubbard, the spokeswoman. The county has grief counselors on hand for colleagues, she said.

Hubbard also said, “The DPIE family will identify ways in which [it can] support Tonya’s children over the upcoming holidays, as well as into the future.”

Also on Monday, U.S. Park Police identified the victim of a shooting at the Fort Washington Marina in Prince George’s as a woman from Montgomery Village.

Tania Vanessa Lopez, 36, and a man were found shot in the parking lot outside Proud Mary’s Restaurant shortly after 1 a.m. Sunday, Park Police said.

Lopez was pronounced dead at the scene, and the 27-year-old man was taken to a hospital, police said. The man, who suffered critical injuries, was in stable condition, authorities said.

Park Police said detectives are pursuing several leads in Lopez’s killing and are asking anyone with information about the case to call 202-610-8737 or e-mail USPP_Tipline@nps.gov. Anyone who provides information can remain anonymous.