A firearm was recovered at the scene where a retired police inspector and his female partner were found dead on Saturday morning in Wiltshire, police have said.
Detective Chief Inspector Ian Saunders from Wiltshire police has said: "The investigation continues to try and establish what led to this tragic incident.
"We have recovered a weapon from the scene. My working assumption is that weapons were discharged and the victims had sustained some form of gunshot wounds."
Post-mortem examinations will be carried out today.
Officers are not looking for anybody else in connection with the shootings, which happened on Moonrakers estate in Devizes.
More top news
Jamie Oliver turned down the offer of playing a hobbit in the movie adaptation of the book by JRR Tolkien, the TV chef has revealed.
Children are being put at risk as 11% of posts for permanent children's social workers remain unfilled, experts have warned.
A Network Rail boss who presided over the Christmas trains chaos will not receive a bonus of more than £300,000 when he leaves in February