Where an individual attempts to adduce expert evidence in aid of their defence, they must have been suffering from a genuine and recognised mental condition, which was capable of producing effects on the mind and body outside the expertise of the tribunal. Thus, in R v Smith,[7] a defendant to murder by stabbing was permitted to call an expert to explain the effects of automatism, which he had been suffering from. It has been made clear that in cases where individuals are merely vulnerable or easily susceptible to suggestion, expert witnesses may not be called in order to testify to such characteristics.