Graham Dwyer to learn outcome of his murder appeal next month

The Court of Appeal has listed the case for judgement on March 24.

The 50-year-old Foxrock architect is seeking a retrial because of the way the trial judge in his case decided to allow phone metadata evidence obtained by gardaí to be put before the jury.

His appeal against his 2015 conviction was heard over two days in December and came after a separate and ultimately successful challenge to the law under which his metadata was retained and seized.

The challenge resulted in rulings in Dwyer’s favour by the High Court, Supreme Court and Court of Justice for the European Union (CJEU).

The metadata proved crucial to establishing a link between Dwyer and his victim and helped detectives to build up a picture of their secret sadomasochist relationship.

The evidence was included in Dwyer’s trial despite opposition from his lawyers.

The Court of Appeal heard Dwyer was no longer arguing for the exclusion of the evidence altogether but believed it should have been the subject to an admissibility test, arising from a Supreme Court case called JC.

His lawyers argued that because such a test was not applied, he was entitled to a retrial.

In the JC case, which was ruled upon shortly after Dwyer’s conviction, the Supreme Court found by a narrow majority that evidence obtained unconstitutionally can be admissible, but only if the prosecution can show the breach was inadvertent.

Dwyer’s lawyers also argued he should have been declared not guilty at his trial because the possibility that Ms O’Hara had taken her own life could not be excluded.

It was further argued that it was prejudicial for the trial judge to allow the jury to view videos of Dwyer engaging in sexual acts with Elaine O’Hara and other women. In the videos, Dwyer could be seen stabbing or pretending to stab the women.

Ms O’Hara (36), a vulnerable woman who had been receiving psychiatric care, went missing in August 2012.

Her remains were found 13 months later in a forest at Killakee in the Dublin Mountains.

Using the 2011 Communications Act, gardaí obtained data associated with Dwyer’s work mobile phone and other handsets. Using cell-site analysis, they were able to pinpoint roughly where Dwyer was at certain points in time based on the movements of his work phone.

This helped investigators establish his routine in the months prior to Ms O’Hara’s disappearance.

Cell-site analysis was also able to link the movements of Dwyer’s work phone to those of a Nokia mobile phone found in the Vartry Reservoir in Co Wicklow in September 2013.

Dwyer denies he owned or operated burner handsets, dubbed the “master” and “slave” phones, which the prosecution alleged he and Ms O’Hara used to communicate with each other.

However, lawyers for the DPP argued that the evidence against Dwyer was overwhelming even if mobile phone data was excluded.

They said old-fashioned detective work was undertaken, including retrieving texts from Ms O’Hara’s phones for information that might identify a suspect.

Dwyer’s DNA was also matched with semen found on Ms O’Hara’s mattress.

They also argued that the trial judge was right to allow the jury to see the videos.

The State also argued against the suicide theory, posing the question that if Ms O’Hara had committed suicide, how did her keys and phone end up in the reservoir.