A Co Wexford man serving a life sentence for the murder of a bank clerk during an armed raid on a bank in New Ross in November 1992 was yesterday refused leave to appeal against his conviction.Edward O'Callaghan (27), with an address at Bosheen Estate, New Ross, Co Wexford, was sentenced in July 1994 to life imprisonment for the murder of Mrs Carol Walsh. He was also sentenced to 20 years for robbery and firearms offences.At the Court of Criminal Appeal yesterday Mr Blaise O'Carroll SC, for O'Callaghan, applied for leave to appeal against conviction. He submitted that the trial judge had erred in law in saying that the issue relating to whether the woman could have been kept alive on a life-support machine should be put before the jury.He argued that the trial judge misdirected himself in the law on the issue of brain-stem death. The judge's action in deciding on the issue in the presence of the jury prejudiced his client, Mr O'Carroll said. He asked the court to quash the conviction and order a retrial.Mr Justice O'Flaherty said O'Callaghan entered the TSB bank in New Ross armed with a sawn-off shotgun. He confronted Mrs Walsh and discharged his shotgun. She was taken to Waterford Regional Hospital and subsequently moved to Beaumont Hos pital in Dublin where she was put on a life-support machine. On November 5th, 1992, three days after the shooting, a consultant pronounced her brain stem dead. Mr Justice O'Flaherty said the defence did not dispute that death was caused by gunshot wounds. In all cases, the trial judge had to have some discretion in the conduct of the trial, and in this instance the court was unable to find any fault in the manner in which he had conducted the proceedings.