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
Francois Hollande has urged British MPs to support David Cameron's plan to launch airstrikes against so-called Islamic State in Syria.
Teenage twin brothers were found guilty today of murdering a 'quiet, humble' father who dared to intervene in a robbery in north London.
Police have warned Black Friday web shoppers to change their passwords after a man was arrested for alleged cyber offences against Tesco.