She had suffered both from the decision of the trial judge, Mr Justice Mantell, to admit key evidence regarded by the defence as inadmissible and from his failure to put her side of the case adequately when he summed up, said Richard Ferguson, QC.
West, 42, is seeking leave to appeal against her conviction on 10 charges of murder by a jury at Winchester Crown Court. But Lord Taylor, the Lord Chief Justice, and two other judges, are effectively hearing her appeal case in full.
The widow of the self-confessed serial killer, Frederick West, who was found hanged in his prison cell, denies any part in the murders of 10 girls and young women. Their remains were found at 25 Cromwell Street, Gloucester, the couple's house, and at their previous home in the city.
West is in jail at Durham and is not attending the hearing in London.
Mr Ferguson told the court yesterday: "Other than the sheer horror of the discovery of the remains of the victims, the most striking feature of this case, say the defence, was the dearth of evidence to connect the applicant to these crimes."
He said the evidence linking Rosemary West to the deaths of Heather West, her daughter, Charmaine West, her husband's step-daughter, and Shirley Robinson, a lodger at 25 Cromwell Street, was "tenuous."
Evidence connecting her to the seven victims of sex killings found at Cromwell Street, "was virtually non-existent unless the evidence advanced under the banner of similar fact evidence was properly admissible".
Similar fact evidence was given by women who survived sexual assaults in which Rosemary West took part with her husband. The prosecution argued this showed that she was also involved in the attacks on the victims who died, but the defence said it was inadmissible.
Mr Ferguson said yesterday it was not known how the victims died because such a long time had elapsed since their deaths; Rosemary West had never admitted being involved, and there was evidence that Frederick West had carried out two murders and other attacks on his own.
The remains of Ann McFall, who disappeared before Frederick West met Rosemary, were found dismembered and bound with cord. Mr Ferguson said this showed that Rosemary West had not been involved in killing the seven Cromwell Street victims discovered in similar circumstances.
He said the possibility that Frederick West was solely responsible for the murders "is the hook upon which the defence hang their objection to the similar fact evidence."
Mr Ferguson continued: "The media both before and during the hearing of the case, exercised a malign influence on the proceedings such as to deprive the applicant of a fair trial."
He produced newspaper cuttings which he said were "sensational and prejudicial" and added that every major witness had a contract with the media which led to the danger of evidence being exaggerated or rehearsed with journalists.
Mr Ferguson said that another reason for the appeal was the defence's belief that the charges relating to Heather West, Charmaine West and Shirley Robinson should have been dealt with separately.
He also criticised the summing-up of Mr Justice Mantell for not giving adequate directions to the jury on how to apply similar fact evidence and failing to put the defence case fully.
The hearing continues today.Reuse content