The brutal murder of Ms. O’Hara shocked and saddened the Republic of Ireland in 2013 when her remains were discovered in the Dublin mountains.

The subsequent investigation and trial painted a disturbing picture of a man who had committed a heinous crime to satisfy his perverse desires.

During the trial, Dwyer’s affair with his victim was revealed, along with the details of their BDSM relationship, in which he was the “master” and she the “slave.” The court heard how Dwyer had long fantasised about killing a woman, which he finally enacted by stabbing Ms. O’Hara to death on Kilakee mountain.

The prosecution’s case relied heavily on mobile phone data evidence retrieved from Dwyer’s work phone, which demonstrated his movements on the day of the murder.

Despite initially winning a case in an EU court about the admissibility of this evidence, Dwyer’s appeal was ultimately dismissed by an Irish Court of Appeal judge on Friday.

The judge confirmed that the mobile phone data was an integral part of the prosecution’s case and that its limited admission could not have given rise to a miscarriage of justice.