Background

Since the 1800’s, the insanity defense has been the subject of widespread controversy and dispute. In general terms, the insanity defense is utilized when a person is accused of a crime, but is not responsible due to mental illness or mental defect. Individuals who are identified to be insane at the time they committed their crime can use the insanity defense to prove that they are not guilty by reason of insanity. In legal language, the term insanity can be associated with non-responsibility because of the drastic effects that mental diseases can have on the mental, emotional, and behavioral conditions of an individual. The insanity defense was developed to help individuals who committed criminal acts in which they are morally blameless for, because of factors outside their control (mental illness). Although the insanity defense, if successful, usually gets individuals acquitted of criminal charges, and prevents them from facing imprisonment, individuals who are found “not guilty by reason of insanity” usually face other implications such as court ordered treatment. However, the insanity defense has both positive and negative components to it. Throughout the progression of the insanity defense, the legal system has struggled to deal with various problems within the structure and usage of the insanity defense such as with the way it is used, the way in which mental disorder can be defined, whether or not it is too lenient, and what evidence or testimony can be included. Ultimately, the insanity defense provides individuals with a way to plead “not guilty” to criminal actions and provides acknowledgement of the harrowing effects of mental illness.

The first known mention of the insanity defense was in England in both the 1500 and 1700s. In 1580, insanity was utilized as a criminal defense by an English legal treatise stating that, “if a madman or a natural fool, or a lunatic in the time of his lunacy” murders someone then they cannot be held responsible for the killing. Later in 1724, the British courts developed something called the “wild beast test,” where a defendant could not be convicted of criminal charges if they understood the crime no better than “an infant, a brute, or a wild beast.” The wild beast test led multiple judges to instruct the jury that they must acquit individuals by reason of insanity. The wild beast test is associated with the insanity defense because both concepts discuss the lack of culpability that an individual has for committing a crime when their mental and emotional state is being impaired by mental illness.

Since the development of the Wild Beast Test, the insanity defense has gone through multiple changes. In the 1800’s, the insanity defense was made concrete in Britain’s legal system, in the 1950’s the insanity defense became more prominent after veterans were facing severe psychological issues from WWII, and various versions of the insanity defense were introduced and then abandoned throughout the twentieth century.

Methods

Throughout the evolution of the insanity defense, various methods have been adopted and repudiated. Many of these methods continue to be used today, while some have been completely disbanded. One example is the Irresistible Impulse Test. This method determines whether or not an individual is unable to control their impulses due to mental illness, which may result in them committing a criminal act. The Irresistible Impulse Test advocates that an individual is not guilty if the person “did not possess a will sufficient to restrain the impulse that may have arisen from the diseased mind.” Although the Irresistible Impulse Test is rarely used today, there are various methods that many states have adopted into their legal system. One of the most prominent methods is the M’Naghten Rule. This legal standard states that a person can be deemed insane, if, as a result of mental disease or defect, the defendant was suffering from a defect in reason that caused them to not know the nature of their act and whether or not the act was wrong. This method is utilized in states such as New Jersey and New Mexico. 

Current Laws

In the United States, there are various interpretations of the insanity defense that vary from state to state. However, each state has a similar definition of insanity that is defined by three main components: the presence of a mental disease or defect, and the inability to control their actions as a result of that defect, and/or the inability to differentiate right from wrong as a result of that act. Some states have abolished the use of the insanity defense while others have rearranged the insanity defense to other verdicts such as “guilty but mentally ill” and “diminished capacity.” For example, the state of Idaho has abolished the insanity defense, but allows for a guilty but insane verdict, while the state of Kansas has abolished the insanity defense in its entirety. However, the decisions of states like Kansas to abolish the insanity defense has not come without significant dissension. Many complaints have filed lawsuits against the state of Kansas which has now been brought to the Supreme Court. Although no decisions have been made yet on how far states can go on restricting and eliminating the insanity defense, the complainants have argued that a ban on the insanity defense takes away recognition of mental health in our justice system. 

The guilty but mentally ill verdict was developed as a hybrid version of the insanity defense where offenders are imprisoned but also receive the appropriate mental health services while they are incarcerated. This verdict was developed as a result of widespread criticism that the insanity defense allows too many people to escape punishment. However, various organizations have criticized the development of the guilty but mentally ill verdict, arguing that American correctional facilities do not have the proper resources and services to effectively treat individuals who suffer from severe mental illness. Other states still utilize standards originally from previous legal determinants, such as M’Naghten Rule and the Model Penal Code. In Iowa, the M’Naghten Rule is used and the burden of proof remains on the defendant. However, New York uses the Model Penal Code Rule and the burden of proof is on the defendant. Contrastingly, in Texas, a person can be deemed legally insane only if the criminal conduct was a result of severe mental disease or defect to the point that the person did not know that it was wrong. Most states have slightly different or entirely different legal interpretations of the insanity defense and have shaped the insanity defense in a way that coincides with their beliefs.

Legal Proceedings

The process of pleading the insanity defense in a trial is more complicated than typical judicial proceedings. Firstly, the defense must request for an evaluation, and an expert will be assigned to the defense for evaluation. The expert will only be assigned for evaluation if there is probable cause that insanity will play a role in the defense. Prior to the trial, the defense is required to give notice of intention to file an insanity plea. This notice must be given at least 21 days before the trial date. During the trial, the defendant is presumed sane and the burden of proof is on the defendant. In the end, the judge or jury makes the final decision on whether or not the insanity defense will be accepted.

Issues

Since the creation of the insanity defense, the practice has been heavily criticized for many reasons. Firstly, many critics of the insanity defense have argued that the practice is widely misused. Some defendants are believed to fake insanity in order to get acquitted or to receive less harsh sentences. For many, they believe that the insanity defense is a way in which guilty individuals can go free and not receive certain punishments such as long-term incarceration. However, in a study conducted by the Washington Post, it was found that in all of the criminal cases in eight states during the 1990’s, less than one percent of defendants plead the insanity defense and only a quarter won acquittals. This study shows that in reality, the usage of the insanity defense is very rare and that few people actually are able to successfully utilize it. In addition, studies by the American Academy of Psychiatry and the Law have concluded that the overwhelming majority of defendants acquitted by reason of insanity suffer from schizophrenia or some other mental illness. This study is important because it refutes the notion that defendants who utilize the insanity defense are faking or misusing it. 

However, one widespread point of disapproval about the insanity defense is the ability for individuals who utilize the insanity defense to get released more quickly. In the past two decades, there has been a significant increase in rapid releases for individuals who plead “not guilty for reason of insanity.” These shorter sentences can be attributed to two main factors: improvements in psychiatric treatment, as well as the equal protection rights and constitutional due process that these individuals are afforded. Various court rulings have determined that insanity acquittees should be afforded the same constitutional due process and equal protection rights as any other individual in the criminal justice system. Since psychiatric treatment in the United States has greatly advanced in terms of patient care and medical treatment, it has been much easier for treatment facilities in which insanity acquittees are most often sent to, to treat their patients. As a result, once a patient “recovers” from mental illness, it is very difficult to continue to hold them in a treatment facility or hospital, therefore resulting in relatively shorter releases than regular incarcerated individuals. 

An additional criticism of the insanity defense is that there are many inconsistencies in terms of validity and reliability. Firstly, in past cases there has been a grey area regarding what mental conditions or mental illnesses qualify for the insanity defense, and whether or not there is a way to confirm those conditions. Two famous cases can be utilized in order to exemplify these inconsistencies that have heavily disparaged the credibility of the insanity defense. In 1982, John W. Hinckley Jr. shot Ronald Reagan along with several other people. During his trial, he was acquitted under the insanity defense and was diagnosed as schizophrenic. However, various people such as professors of law and psychiatrists said that he did not match the criteria of a schizophrenic, and that his exact diagnosis was not a real condition. This case highlights the inability of the law to impose credible and consistent standards for the insanity defense, and led to the creation of the Insanity Defense Reform Act. This act requires defendants to prove the defense of insanity through clear and convincing evidence. The second case occurred in 1982, when a man named Lloyd Grass was accused of stabbing his wife multiple times in the neck and chest. During his trial, Lloyd pleaded insanity and was diagnosed as having a brief psychotic episode brought on by various factors such as dehydration and diet. Lloyd’s insanity plea was accepted and he was transferred to a mental hospital to receive treatment. However, two weeks later, psychiatrists found that Lloyds condition had disappeared without receiving any treatment. Months later, Lloyd Grass was released from the mental hospital and was able to walk free. This case highlights the many inconsistencies and validity issues associated with the insanity defense. Although many components of the insanity defense have changed since these cases, similar criticisms of the insanity defense are discussed today.

Cases

After the Insanity Defense Reform Act was implemented, various standards regarding the insanity defense were changed. The act made it much harder for defendants to successfully plead not guilty by reason of insanity. For example, in 1991, Jeffrey Dahmer was convicted of killing 15 young men as their mutilated and cannibalized bodies were found in his apartment. Although Jeffrey pleaded not guilty by reason of insanity, his plea was rejected and he was sentenced to 15 consecutive life sentences without the chance of parole. The reason why Jeffrey Dahmer’s insanity defense was rejected is because the jury did not see clear and convincing evidence of how Jeffrey Dahmer’s mental condition caused him to commit the crimes without understanding the wrongness of his actions. This conviction was seen as the end of the insanity defense and a counterpoint to the Hinckley acquittal. Many believed that if someone like Jeffrey Dahmer, who committed such heinous and vial acts, could not be found insane, then who could? A similar example to this case occurred in 1997 when a man named John Du Pont  shot and killed a famous wrestler named David Schultz in his driveway in front of Schultz’s wife. During his trial, the defense and the prosecution argued that Du Pont was mentally ill. The defense argued that Du Pont was a paranoid schizophrenic and had killed Shultz because he believed that Shultz was part of an international conspiracy to kill him. On the other hand, the prosecution argued that Schultz was mentally ill, but still guilty of the crime because his mental illness did not affect him to the point where he did not understand the wrongfulness of his crimes, which is a pivotal part of the insanity defense. In Pennsylvania, the criminal code utilizes the M’Naghten rule which allowed the prosecution to prove that Schultz, although mentally ill, was coherent and understanding of his actions. In the end, the jury rejected the insanity defense and convicted Du Pont of third degree murder. Both the Du Pont and the Dahmer case represent significant changes in the insanity defense after the Insanity Defense Reform Act. The insanity defense became much more unsuccessful and harder for the defense to prove. Today, the insanity defense is rarely utilized and when it is, it is rarely successful in getting the defendant acquitted.

Conclusion

Throughout history, the insanity defense has played a controversial role in many legal systems around the world. Past its criticisms, the insanity defense serves as the first legal recognition of the influence that mental illness can have on people’s behaviors. The insanity defense has improved the standards of mental health treatment that individuals in the justice system receive, while also, exposing various issues within our legal system. The insanity defense is both a positive and a negative component of our legal system that will require extensive review and reform to ensure its legitimacy and effectiveness. Today, various NGOs have been working towards developing educational campaigns regarding the justice system and mental illness. Specifically, a coalition of NGOs have introduced an act called the Mental Illness Contribution Defense which is a reformed version of the insanity defense with greater clarification and regulations. Insanity defense reform is long overdue and  it will only better the criminal justice system as a whole.