who must determine whether a defendant was insane at the time of a crime
Insanity defense The defense is based on evaluations by forensic mental health professionals with the appropriate test according to the jurisdiction. Their testimony guides the jury, but they are not allowed to testify to the accused's criminal responsibility, as this is a matter for the jury to decide. Similarly, mental health practitioners are restrained from making a judgment on the issue of whether the defendant is or is not insane or what is known as the "ultimate issue".[8]
Trial by jury in Scotland Criminal procedure in Scotland is generally regulated by the Criminal Procedure (Scotland) Act 1995 (as amended) and various Acts of Adjournal passed by the High Court of Justiciary. Under Scots law a jury in a criminal trial must have at least fifteen jurors for a case to continue, and at least eight jurors must declare guilt into order to convict. The jury has a choice of three verdicts: guilty (a conviction), not guilty (acquittal) and not proven (also acquittal).