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
Employment Minister Priti Patel has launched a scathing attack on the government's 'chaotic' immigration controls.
Hanako died peacefully in a Tokyo zoo after living alone for 67 years.
A hearing found Kirsten Treasure guilty of 'shocking' catalogue of misconduct, including refusing to respond to a manslaughter crime scene.