Criminal evidence and procedure – Supply of drugs – Opinion and expert evidence – Sheriff's charge. High Court of Justiciary: Refusing an appeal by an appellant who was convicted of a charge of being concerned in the supply of cocaine, the court held that while there had been a misdirection by way of an omission to say anything about the function of expert evidence, the sheriff's failure to give a direction on a police STOP officer's evidence was not material: there was an abundance of evidence before the court for the jury to draw the necessary inference that the appellant was involved in supply.