Ronald Dunbar, aka Ronald McManus, aged 47, denied murdering Melissa Mahon between September 14 and 30, 2006. He was jailed for life by Mr Justice Barry White after being found guilty of her manslaughter following a 25-day trial in May 2009.
McManus’s trial heard that he strangled the 14-year-old and dumped her body in a river in Co Sligo.
At the Four Courts yesterday the three-judge court, with Ms Justice Fidelma Macken presiding, ruled that Mr Justice White “had imposed an appropriate sentence” and dismissed all grounds of the appeal.
McManus was not in court for the judgment.
In his appeal, his lawyers contended his sentence was too severe and should be set aside on grounds including that the trial judge had shown evidence of bias against McManus.
It was also claimed the judge erred by agreeing with the prosecution that the offence was at the high end of the scale when the DPP had adduced no evidence that serious violence was inflicted on Melissa nor were there any signs of injuries to her.
It was further claimed that the judge erred by placing excessive weight on McManus’s prior convictions, on the issue of the disposal of Melissa’s body, and in the manner in which the judge treated the state’s inability to establish her cause of death.
The DPP opposed the appeal and argued the sentence should remain in place.
The CCA had previously ruled that McManus’s conviction was safe, and had dismissed his claims that he did not get a fair trial.