Charles County sheriff's officers responding to a domestic disturbance call Friday morning in Waldorf discovered the bodies of two people. Investigators believe a man who lived in the house with his mother killed her with a shotgun before taking his life.

Officers went to the residence in the 3100 block of Apple Creek Lane in Waldorf at 11:46 a.m. after receiving a call from a relative, who said the man was arguing with his mother, Sheriff Frederick E. Davis said.

Louis John Lincoln Jr., 46, and Rita Virginia Lincoln, 66, were pronounced dead at the scene. No one else was home, Davis said.

Davis said a relative was talking with Rita Lincoln by telephone when she heard the pair arguing. The woman then called 911 to report a domestic disturbance and went to the house, where she saw Louis Lincoln's body and called 911 again, Davis said.

"All indications are it is a murder-suicide," Davis said.

Capt. Joseph C. Montminy, who was investigating the case, said Friday that it was not clear what the two had been arguing about or what may have led the man to possibly kill his mother.

"The people that we're talking to said that this came out of left field, that they weren't fighting about anything," Montminy said. "In fact, there was a brother of the suspect who talked to the mom earlier in the day, and everything seemed fine. Whatever came up, came up suddenly."

Montminy said Louis Lincoln had no history of violence. It was not clear whether neighbors were home when the shootings occurred. One house next door to the Lincolns' home is for sale, Montminy said.