Harry Tooze, 67, had been shot in the head at close range. The body of his wife, Megan, 65, was lying close by. It is believed both were shot in the house and their bodies dragged into the cowshed.
Their only daughter, Cheryl Tooze, 34, a laboratory assistant, was travelling from her home in Kent to identify the couple, who had run the small holding at Llanharry, Mid Glamorgan, for 30 years.
A team of 40 officers sealed off the two-storey farmhouse and adjoining cowshed. A pathologist and a ballistics expert were called in. Detective Superintendent Colin Jones said no motive had been established and no weapon had yet been found. One theory is that they disturbed an intruder.
Police were alerted when a neighbouring farmer failed to get any response from the house. He had been contacted by the couple's anxious daughter, who telephoned her parents every day and had been unable to get a reply.
Mrs Tooze's cousin, Mary Austin, 65, revealed how the couple were frightened after a shotgun was stolen in a break- in seven months ago.
Police were studying similarities between the murder and an unsolved killing of a brother and sister 70 miles away more than seven years ago.