Firstly, the fact that the law dates back so far can never be a positive point. Society and its views have changed a great deal since the nineteenth century including views on insanity. Since this time, much more research has been carried out on all manners of mental illnesses and much more is known about them. Perhaps at this time, epilepsy and sleepwalking would have been considered to be sufficient and acceptable to be put in a mental hospital for, whereas many would now disagree with this view.
This links in to the second point; that it can be argued that the law’s medical irrelevance is a disadvantage against it. A ‘disease of the mind’ does not have to be a medical problem with your brain. Surely those who plead insanity should actually have mental problems. Firstly it is unfair to those who have to have to plead not guilty due to reasons of insanity to avoid having to plead guilty, and then be sent to a mental institute to try and cause a disorder such as epilepsy as a result. Secondly it is unfair to those who decide they do not want to go down that route and plead guilty to a crime they had no intention or wish to commit, and therefore no mens rea. For example, in Burgess (1991) the defendant and a friend were asleep at his flat when he attacked her in the night with a bottle of wine and the video player. She sustained quite serious injuries to the head and he claimed he was sleepwalking and therefore had no control over himself. He tried to plea automatism but the trial judge would not allow it and directed that insanity was the correct plea because it was an internal factor that affected his behaviour and not something that could be removed to extinguish the behaviour. He pleaded not guilty and then appealed, but the Court of Appeal dismissed it. Many would argue that this was an unjust decision as sleepwalking does not need treatment as extreme as being sent to a mental hospital for an indefinite period of time and may possibly be cured by something as simple as therapy or locking your bedroom door at night.
Another problem with this law is if someone heard voices telling them to kill somebody and they followed the orders it does not necessarily mean that they will be able to use the defence of insanity. If they do not fulfil the need to lack the knowledge that what they are doing is wrong in the eyes of the law, even if they do not fully understand what is happening, then they cannot use that defence. They may succeed with a partial defence of diminished responsibility instead though. However some may say that this is not good enough as someone hearing voices is obviously in need of treatment and should not be sent to a normal jail when they need help.
A final problem with this law is that it can result in irregular and seemingly irrational decisions. For example, in Quick (1973) and Hennessy (1989), both were sufferers of diabetes and yet both had very different outcomes. Quick was a nurse at a mental hospital and attacked a patient after taking his insulin and not eating anything. He pleaded not guilty to assault as he was suffering a hypoglycaemic (low blood-sugar) episode and the trial judge ruled that this was a plea of insanity. Quick pleaded guilty and appealed. The Court of Appeal quashed his conviction on the grounds that it was not his diabetes that caused his behaviour but the insulin he took, and so was an external factor and a plea of automatism should have been left to the jury. However, in Hennessy the defendant was seen getting into a stolen car and driving away. He was charged with taking a car without consent and whilst disqualified but claimed he did not remember taking the car as he had not taken his insulin for three days in a row and had suffered a hyperglycaemic (high blood-sugar) attack. The trial ruled that this amounted to insanity and he pleaded guilty and appealed. The Court of Appeal upheld his conviction on the grounds that it was his diabetes that caused the automatic state, an internal factor.
So, all in all it is easy to tell that this area of law needs a great deal of reform. Any law that is unfair is of great importance to change as soon as possible, as this can decide the course of a person’s life, but one as significant as this is of particular interest. It’s reform would not only benefit the individuals it directly effects but also the institutes that admit people who don’t need to be there when they are already over-crowded and understaffed. This law is not up to date with current views in society and it is long overdue for change.
