Lord Carloway

In an intervention recommending careful consideration of the use of such evidence, the judge said lawyers should take “great care” when deciding if such videos should be screened in court.

In a written judgment following the failed appeal of murderer Paul Smith, 44, he wrote: “The images of the murder of the deceased were horrific; showing in graphic terms the stabbing … and its fatal aftermath.

“Great care must be taken by both prosecution and defence when deciding whether it is necessary to show such images to members of the jury.

“It may be that some may be familiar with this type of image, but many more will not. The lasting effects of viewing such images may be significant. Those effects must be guarded against.”

Lord Carloway said: “The impression left by the trial judge’s report is that the salient parts of the recording were shown repeatedly to the jury. Whether that was necessary … is doubtful.

“It is understandable that, faced with a plea of provocation, the Crown will reasonably deem it necessary to show the images to the jurors. The manner in which that should be done ought, in the future, to be the subject of a considered case management decision.”