Devon and Cornwall Police are continuing their work as part of the triple murder investigation, following 155 priority lines of enquiry - having seized 300 exhibits.
Police were called at around 3pm on Monday, February 11, to an address in Bonhay Road following the discovery of the body of 80-year-old Anthony Payne. His next of kin have now been informed.
Police arrested a 27-year-old man on suspicion of murder on Tuesday - he remains in police custody at Heavitree Road Police Station. On Thursday, February 14, Exeter Magistrates' Court granted a warrant to allow police an additional 36 hours to question the suspect further.
Police are working closely with colleagues in the Crown Prosecution Service and officers currently have until just after 10pm on Friday to detain the suspect in custody.
Following the post mortems, which were completed yesterday, it has been confirmed that all three victims sustained serious head injuries.
Superintendent Matt Lawler added: "Following media appeals, further important witnesses have come forward with highly relevant information. We therefore would like to sincerely thank the public for their support, and re-issue our appeal for further information. Our neighbourhood teams remain out on foot patrol providing advice, support and answering questions.
"We are working with local partners to provide reassurance and support to the vulnerable or elderly in our community. As part of that, since yesterday local neighbourhood staff have specifically visited nine addresses in order to confirm the safety of occupants. There is no information to indicate a threat to any other person – this forms part of our normal support to the vulnerable which, given the circumstances, we have obviously stepped up in our efforts with partners.
Detective Chief Inspector Roy Linden said: "The investigation into these incidents remain connected. Due to the injuries sustained by all three victims and the presentation of the properties, and the age of the victims, we are treating this as a single multiple murder investigation.
Police have asked that anyone who was in the area of Bonhay Road and Cowick Lane between 8am on Sunday, February 10 and 1pm on Tuesday, February 12 and may have seen anything relevant to get in touch with police.
Anyone with information is asked to contact police on 101 quoting log 283 of February 13 or Crimestoppers anonymously on 0800 555 111.