A conviction for culpable homicide has been reduced on appeal to one of assault, where the extent to which the injuries inflicted by the appellant contributed to the victim's death was no more than speculative.

The Criminal Appeal Court gave the ruling in allowing an appeal by Weir MacKay, who went to trial along with Allan Doherty on a charge of murdering Karen Young at a flat in Port Glasgow. Doherty was convicted of murder and MacKay of culpable homicide. The charge narrated seizing the deceased, compressing her neck and restricting her breathing, forcing a hand into her mouth and repeatedly inflicting blunt force injuries on her head and body. Mackay's conviction was restricted to: "you did... repeatedly inflict blunt force injuries on her head and body and you did kill her".

The two accused, the deceased and others had been in Doherty's flat taking drugs. There was evidence that at some point the deceased had put a wrap of drugs in her mouth and begun to choke on it. Doherty had put his hand in her mouth to try and retrieve it but his hand got stuck. He had also compressed her neck to try and stop her swallowing. The appellant told the police he started pumping the deceased's chest as she was choking. The post mortem report gave the cause of death as compression of the neck and drug intoxication, with blunt force injuries to the head as a potential contributing cause. The doctor explained that this could have been due to added stress creating an adrenaline surge leading to potentially fatal cardiac arrhythmia.

For the appellant it was submitted that there was no direct evidence of him carrying out any assault personally. The verdict against him related to injuries that the doctor had confirmed as not the direct cause of death and the evidence fell far short of establishing them beyond reasonable doubt as a substantial contributing factor. The Crown argued that the judge had given correct directions as to what was required to convict; death could have more than one cause and it was sufficient the an assault had contributed significantly to the death. There were multiple blunt force injuries that were not trivial.

Giving the opinion of the court, Lord Turnbull, who sat with Lord Justice Clerk Lady Dorrian and Lord Pentland, said it was clear that the jury had not accepted that the appellant had "associated himself with whatever was going on", so as to convict on the basis of concert. While the injuries for which the appellant was responsible could not be described as trivial, the question was whether there was a basis on which the jury could have concluded that the victim died because of a cardiac arrhythmia. 

He concluded: "There was of course no evidence that the victim in fact suffered a cardiac arrhythmia and we are satisfied that what Dr Turner was describing was no more than a theoretical possibility... 

"The distinction between the present case and the cases of Johnston [2009] and McDade [2012] is that in both of those cases the actual mechanism of death was established in evidence. Once that is known the jury can come to consider whether the conduct established against the accused person made a material contribution to bringing about death through the mechanism as established... In the present case the assault for which the appellant was held responsible may have contributed to the victim’s death, but only on the basis of a mechanism of death which could in the circumstances be no more than hypothetical...

"When the exercise of stripping out the blunt force injures for which Doherty alone was responsible is contemplated it becomes even clearer, in our opinion, that any link between the injuries for which the appellant was held responsible and the death of the victim becomes entirely speculative. In these circumstances we are persuaded that the submissions for the appellant should be given effect to."

The appeal against sentence was continued to he heard at a later date.

Click here to view the opinion of the court.