A man is suspected of killing his wife and daughter before turning the gun on himself. The Spotsylvania Sheriff's Office said the deaths of three people have been ruled as a murder-suicide.

Authorities in Virginia believe that 69-year-old Robert Scully fatally shot his 68-year-old wife Mary Scully and his 38-year-old daughter Meghan before killing himself.

A medical examiners' report confirmed Robert was the only victim to have suffered an apparent self-inflicted gunshot wound.

According to WTVR, deputies visited a Spotsylvania County home in the 70900 block of Waterford Drive around 3.30pm on Saturday (25 November).

The homeowner's pet dog had been running around the neighbourhood and the house's front door was left open.

Officers made several attempts to call out to the occupants before noticing a person inside the home was slumped over in a chair, WTVR reported.

Meghan was found dead from a gunshot wound and officers also found the bodies of her parents. The weapon believed to have been used in the incident was found at the scene.

Neighbours told NBC Washington that they were stunned by the deaths. Some said that although the family had lived in their home for decades, Mary and her adult daughter, who was disabled, were never seen.

"I think a lot of people are walking around with a lot of hurt and pain. You see [them] every day and you don't realise how bad it is for them," a neighbour said.

Anyone with information regarding the incident is asked to call the Spotsylvania Crime Solvers at 1 800 928 5822 or 1 540 582 5822.