Gardai in a major cold case review are investigating if a woman was strangled to death by a man well known to her who then dumped her body in a ditch.
This week officers made a fresh appeal for information in the case of mum-of-two Marie Tierney (34), who they believe was savagely murdered by a man in October 1984.
While no arrests have been made, a prime suspect is still alive and gardai have been investigating Ms Tierney's murder for a number of months.
"This was not a random attack. There is no doubt about that," a source said.
Officers have interviewed a number of people with knowledge of the case.
Medical experts determined in 1984 that the "probable cause" of Ms Tierney's death was manual strangulation.
The Herald can reveal that officers are working on the theory that Ms Tierney was attacked in a house and murdered.
She is then thought to have been driven to a location nearby, where her body was dumped in a ditch.
Her badly decomposed remains were not found until two months later.
Gardai said Ms Tierney left her home on the night of October 21, 1984.
Her car was found the next day, while her body was discovered in a ditch on Bleach Road, Kilkenny, two months later.
To date, more than 500 lines of inquiry and 200 witness statements have been recorded.
"Marie Tierney was a married woman with two children aged 12 and 13," said a spokesman.
"She resided with her husband and their two children at Clintstown, Co Kilkenny, where they ran a grocery store and petrol station.
"Marie Tierney (34) was reported missing on October 22, 1984, by her husband.
"She left their house on the evening of October 21 at approximately 10.30pm in the family car, a Renault 18 Estate, registration number 35-HIP.
"An investigation by gardai located the car at Newpark Fen, Kilkenny, later that day.
"A number of searches were conducted by gardai and members of Marie Tierney's family and friends but Marie could not be located.
"On December 21, 1984, the body of Marie Tierney was located by a male out walking on the Bleach Road in a ditch."