Killeen and Wayne Dundon were convicted of murdering Roy Collins in July 2014
Nathan Killeen has failed to convince the Court of Appeal to set aside the dismissal of an appeal against his conviction for murdering Roy Collins.
The innocent businessman was shot dead in Limerick in April 2009 and Killeen was found guilty for his role in the murder five years later.
On April 9th 2009, Roy Collins was shot at his arcade at Roxboro Shopping Centre in Limerick.
It is believed his father Steve was the intended target for his role in securing a previous prosecution against notorious Limerick criminal Wayne Dundon.
The gunman was found guilty of murder one year later, while Dundon and Nathan Killeen were convicted for their roles in July 2014.
Dundon and Killeen unsuccessfully appealed their convictions three years later, and Killeen sought to have his dismissal overturned.
His lawyers claimed the judgement was delivered on a false premise and tried to have it set aside and his case reheard by a different court.
He raised issues about search warrants, DNA swabs and what he claimed was the non-disclosure of certain materials, but the three judge panel rejected his appeal this morning and he was taken back to Portlaoise prison where he's serving his life sentence for murder.