Two people convicted of stabbing a woman to death in Shetland claim they have fallen victim to miscarriages of justice.
Ross MacDougall, 33, and Dawn Smith, 29, had denied murdering Tracy Walker, 40, in Lerwick in July 2019.
MacDougall was jailed for a minimum of 23 years and Smith was ordered to serve at least 20 years and two months.
Lawyers told the Court of Criminal Appeal the trial judge made mistakes when giving legal directions to jurors.
Lady Dorrian, Lord Pentland and Lord Turnbull were told that the duo should have their convictions quashed.
Jurors at the High Court in Edinburgh found them guilty last year, after hearing the pair had wanted money to buy drugs.
Jailing them for life, Lord Uist said it was a "shocking and gruesome" murder of an innocent woman.
He told MacDougall his criminal record showed he was an "evil man".
The judge then told Smith: "You encouraged or instigated your co-accused to commit this murder and supplied him with a knife which he used. Your guilt is at least as great as his."
At the Court of Criminal Appeal, MacDougall's advocate Brian McConnachie QC said Lord Uist had told jurors that they could convict Smith of murder if they were satisfied that she "acted in concert" with MacDougall.
He said that this direction ignored evidence which could show that Smith alone killed Ms Walker.
'That direction was wrong'
Mr McConnachie said that by doing this, the jury were deprived of the ability to consider the possibility that it was Smith and not MacDougall who assaulted Ms Walker.
He said: "The learned trial judge indicated that the only basis the jury could convict Dawn Smith was on the basis of concert with Ross MacDougall - you could not convict her of murder if you were not satisfied that if she was acting in concert with him.
"In my submission the learned trial judge is giving a very specific direction - he is directing them that in relation to the second appellant she can only be convicted on the basis of concert.
"My submission is that direction was wrong; it was a misdirection."
Mr McConnachie also told the appeal judges that the 23-year term imposed on MacDougall was excessive.
Advocate Paul Nelson for Smith said that Lord Uist failed to address the possibility that another person could have handed MacDougall the knife used in the attack against Ms Walker.
Mr Nelson also asked for Smith's sentence to be reduced.
Judge Lady Dorrian told the lawyers that the court would issue its judgement in the near future.
She added: "We will take time to consider our decision and we will issue our decision in writing."