Desmond Wooding was found dead in his Worcestershire home with stab wounds on Monday morning.
Police say the pensioner, who lived alone in Vines Lane, Droitwich, was last seen alive on Sunday evening near to his house.
Mr Wooding was regularly seen driving his mobility scooter in the area.
Police have issued CCTV of a man seen walking his dog in the area last weekend and believe he may have information that could be vital for their enquiry.
“I would urge members of the public to think back to the weekend, what they were doing, and whether or not they saw or heard anything suspicious”
Det Chief Insp Carl Moore
Detective Chief Inspector Carl Moore, of West Mercia Police, said: “This is a tragic case, whereby an elderly gentleman has been killed in his own home.
“I would urge members of the public to think back to the weekend, what they were doing, and whether or not they saw or heard anything suspicious.
“We are also looking to speak to the man in the images and video footage, who we have not yet spoken to, and may be able to assist with our investigation.”
Superintendent Damian Pettit said: “We recognise that this is a shocking incident for the local community, but incidents such as these are thankfully rare, and our thoughts remain with Desmond’s family and friends at this time.
“Anyone with any concerns can speak to a member of my team, as we remain in the area carrying out our inquiries.
“This investigation is being led by our Major Crime Investigation team, and I would like to reassure the community that finding out who is responsible for this crime is our utmost priority.”
Anyone with any information is asked to contact West Mercia Police on 101 or call Crimestoppers on 0800 555 111.