The Court of Criminal Appeal has reserved judgement in the case of a Dublin man who was sentenced to life imprisonment in 2011 for shooting a man in front of his family.
Keith Wilson (aged 25) from Cremona Road Ballyfermot was found guilty of fatally shooting Daniel Gaynor (aged 24) in Finglas in August 2010.
Keith Wilson's barrister Dominic McGinn SC today told the Court of Criminal Appeal that it was wrong to rely solely on DNA evidence in the absence of other connecting evidence.
He said that Mr Justice Garrett Sheehan had told the jury they were the deciders.
However, Mr McGinn also said "more compelling evidence would have put Mr Wilson at the scene - it is wrong to rely solely on a scientists evidence in the absence of connecting evidence."
He added that the judge should have given something along the lines of a warning to the jury of the absence of corroboration.
Alex Owens, SC for the State, said that no such warning should have been given and that the method used by gardaí to obtain DNA had been necessary, due to Wilsons refusal to co-operate.
Mr Owens told the court that gardaí had taken cigarette butts discarded by Wilson and that they had been relied upon after he had refused to provide body samples.
Mr Justice Liam McKechnie, presiding, said the appeal court would reserve its judgement.