Robert Simpson, 67, also known as Ronnie, walked with the aid of a stick and was found dead in his home in Mayfield Drive, Armadale, just after 9pm on Saturday. He had suffered serious head injuries.
Officers had knocked on his door on Friday night after being called to a disturbance, but left after no-one answered and there were no signs of trouble.
But Mr Simpson’s son, Ross, 31, who is recovering after being stabbed less than 24 hours before his dad’s body was found, yesterday posted on Facebook: “The police did go to the house but never tried the door – pure f***** up.”
Lothian and Borders Police insisted officers had responded but found nothing untoward. A spokeswoman said: “Officers did attend the address and the homes of neighbours.”
Ross Simpson, whose sister, Kay, discovered their father’s body, also wrote in the internet message: “He never deserved anything like what happened to him. He was a frail old man that never had a chance.”
Police yesterday released CCTV images of the retired plasterer, which show him visiting a shop on South Street near to his home at around 12.45pm last Wednesday.
There have been no confirmed sightings of Mr Simpson after that date, although one neighbour told the News they had seen him the following day.
More than 40 police officers are working on the inquiry, and it is understood there has been nothing to suggest Mr Simpson’s murder was connected to his son’s stabbing.
Detective Superintendent Bob Cowper said: “The response from the local community so far has been impressive and I would like to thank those who have come forward so far with information.
“Unfortunately it hasn’t yet brought us any closer to finding Mr Simpson’s killer, and we still have no obvious motive.”
Ross and Kay said in a statement: “We loved our father very much, and we are so devastated by our loss. He’ll be missed by everyone who knew him.” Following the attack on Ross Simpson, two men from West Calder appeared in court charged with assault, but both made no plea or declaration. A 24-year-old was remanded in custody while a 28-year-old was released on bail.