Appeal by serial killer Mark Nash will not be heard by Supreme Court

Nash was found guilty in April 2015 of murdering Sylvia Sheils (55) and Mary Callanan (67), whose mutilated bodies were found in sheltered accommodation in Grangegorman between March 6 and 7 1997.

Oiginally from England but with last addresses at Prussia Street and Clonliffe Road in Dublin, Nash denied the murders.

He was unanimously found guilty by a jury after a 48-day trial at the Central Criminal Court and jailed for life.

Nash was already serving life since October 1998 for murdering two other people in Ballintober, Castlerea, Co Roscommon in mid-August 1997.

Last May, the Court of Appeal dismissed his appeal over his conviction for the Grangegorman murders.

It said there was clear justification for the jury to determine the women's DNA profiles on Nash’s jacket were present on his jacket from the time of the double murder.

He sought a further appeal to the Supreme Court but, in a recently published determination, a three judge court said Nash had not met the criteria for an appeal as he had not shown the case raised a legal point of general public importance or an appeal was necessary in the interests of justice.

Nash, it noted, was arrested in August 1997 in connection with other matters and at that time made admissions in relation to the Grangegorman murders.

Another man, Dean Lyons, having previously made detailed admissions in relation to the same murders, was in custody charged with the murders. Mr Lyons later retracted his admissions as did Nash. Mr Lyons died in 2000.

For reasons including absence of any forensic evidence associating him with the crimes, Nash was not prosecuted for the murders.

Following further DNA testing in 2009 using new tests, evidence of the DNA of both victims was found on Nash's clothing and he was charged with the murders.

The defence called expert evidence of a risk of contamination, which was disputed by the prosecution.

In seeking a Supreme Court appeal, lawyers for Nash argued an issue of general public importance arose over whether the Court of Appeal was right to uphold the trial judge's decision that the risk of contamination dispute should be left to the jury.

Having concluded “the extensive scientific evidence given to the jury did not conclusively prove or disprove contamination”, the Court of Appeal said that issue was for the jury.

The Supreme Court said the Court of Appeal ruling involved application of well-established law to the facts of this case and Nash had not advanced grounds for a different test to be applied when the relevant evidence in dispute is scientific evidence.

A second question of general public importance Nash sought to rely upon related to an alleged invitation by the trial judge to the jury to “speculate” as to the content of certain statements of Dean Lyons which had not been led in evidence.

Extracts selected by the defence and prosecution from some statements of Mr Lyons had been admitted in evidence, it noted.

The Court of Appeal had dismissed as "baseless" the claim the jury was asked to "speculate" as alleged.

The Supreme Court ruled Nash had failed to show any point of general public importance arose from that second ground.

The Appeal Court finding in that regard was based upon the particular facts of the trial, having regard to the exchanges between counsel and judge, including requisitions and the judge’s charge, it said.

In finding an appeal was also not necessary in the interests of justice, the court said Nash has already had a full appeal to the Court of Appeal and a detailed judgment considering and determining each ground of appeal.