A Wicklow man has lost his bid to overturn his conviction for murdering a man in front of his young son.

Following a retrial five years ago, Garrett O’Brien of Clover Hill in Bray was convicted of the murder of 27-year-old Seamus O’Byrne.

He argued his arrest was unlawful and raised concerns about some of the directions given to the jury by the trial judge.

On March 13th 2009, Seamus O’Byrne and his girlfriend Sharon Rattigan were preparing to leave their home in Tallaght with their baby boy.

While she was putting their child into their car, a man in dark clothes with a hooded tracksuit top walked up to Mr O’Byrne and shot him four times

Ms Rattigan ran towards them and was shot in the leg. Despite that, she managed to tackle the gunman and disarm him.

His hood flew back when they tumbled into an adjoining garden and she was able to see his face properly.

She eventually let go of him because her child was screaming and he ran off - leaving behind his gun, a can of red bull and a mobile phone.

Gardaí believed Mr O’Byrne was targeted because his girlfriend is a sister of Brian Rattigan – who is serving a life sentence for murdering 21-year-old Declan Gavin outside a fast food restaurant in Crumlin in 2001.

Garrett O’Brien was identified as a suspect when Gardaí traced the phone left at the scene back to him.

He blamed another man and denied having any part or knowledge of what happened - but was convicted of murder following a retrial in 2012.

He appealed his conviction on a number of grounds including his claim that the trial judge made a mistake when he ruled that his arrest was lawful.

His lawyers also made submissions in relation to the directions given to the jurors before they began their deliberations.

They also argued that the judge should have asked for a detailed explanation as to the breakdown of its verdict, but the Court of Appeal disagreed and decided there was no basis to support such a claim.

The judges rejected all the other grounds too and dismissed the appeal.