An expert witness has changed his mind over whether a series of phone calls made to a pensioner's home after she was battered to death with a crucifix was answered.
Telecommunications expert John Tarpey was called to give evidence by lawyers representing Karen Walsh, who was convicted of murdering Maire Rankin in her Co Down home in 2008.
Mr Tarpey's initial view was that three phone calls to the 81-year-old victim's home after her death were most likely picked up.
But yesterday he told the Court of Appeal that after studying phone billing records, this view has now shifted.
He said: "I can't be sure they were answered and, on the balance of probabilities, they probably weren't answered."
Pressed further, the expert described his belief as being on the boundary between a probability and a strong probability.
Despite the assessment, counsel for Walsh claimed the original trial process had been so flawed that her conviction for murdering Mrs Rankin in the early hours of Christmas Day 2008 should be overturned.
Frank O'Donoghue QC argued that misdirections to the jury rendered the verdict unsafe - even if it is concluded that "an abundance of evidence" points to her guilt. Mr O'Donoghue insisted: "This verdict is unsafe and, if that's the case, ought to be retried."
However, Liam McCollum QC, prosecuting, referred the judges to his earlier submissions that the evidence against Walsh was overwhelming.
Dealing with the telephone calls, he added: "To suggest there could be any conclusion other than the phone was answered is untenable."
Mrs Rankin was found dead in the bedroom of her Dublin Road home in Newry.
The victim, a devout Catholic, had suffered up to 15 broken ribs and been beaten with a crucifix given to her as a wedding gift.
Evidence of a sexual assault - thought to have been carried out to cover the killer's tracks - was also discovered.
Walsh, a Dublin-based pharmacist who often stayed at a house she owned next door to the murdered pensioner, is currently serving a minimum 20-year prison sentence for carrying out the deadly attack.
During her trial, the prosecution claimed she arrived at Mrs Rankin's home already drunk and with a bottle of vodka. It was alleged that the mother-of-one flew into a rage and attacked the pensioner after being chastised about her drinking.
Despite being found guilty of murder, Walsh continues to protest her innocence.
As her four-day appeal hearing drew to a close in Belfast yesterday, the victim's family once again packed the courtroom.
Walsh's accountant husband Richard Durkin sat just a few feet from them in the public gallery. The three senior judges hearing the appeal reserved their decision.