Unit 07: the role of mental illness in court. Textbook chapter 8: the role of mental illness in court. Two elements must be present in order for criminal guilt to be established (actus reus, mens reus) Both elements must be found without a reasonable doubt for a guilty verdict to be reached. Issues of fitness, insanity, automatism, and mental disorders all call into question these two basic elements to criminal law. In order to be charged with a crime and tried fairly an individual must have some understanding of the charges and proceedings and be able to help in preparing their defence. In r. v prichard they established 3 fitness standard criteria: whether the defendant is mute of malice (intentionally, whether the defendant can plead to the indictment, whether the defendant has sufficient cognitive capacity to understand the trial proceedings. In r v. taylor - ontario court of appeal applied terms of.