Guideline for Determining the Criminal Liability and Security Measures for Insane Offenders

Abstract

Criteria for determining the criminal liability of mentally disordered offenders have long been a problem for courts and lawyers. Since some offenders may commit crimes without realizing it or the crimes were caused by impairments in the nervous system, brain, mind, emotions, and stress. The problem is what level of mental disorder will be taken into consideration that a person is not guilty or is guilty, but the punishment should be exempted, or the penalty should be reduced. The Common Law Courts in the United Kingdom laid down the principle in McNaghten’s (1843) case that all human beings must be presumed to be mentally sane unless it can be proven that while committing the offense, the defendant was suffering from a mental illness to the extent that he did not know the content and essence of the act. That means the offender is unable to know whether his action is right or wrong. These principles have been widely adopted in the United States and countries in the European region. This led to the result that the defendant would be convicted of not guilty, and the court would order the defendant to be detained for treatment at a hospital.

As for the liability of persons with mental defects, psychosis, or mental infirmity, according to the Thai Criminal Code, if the doer is not aware of the action, he will not be guilty under Section 59. However, if the doer is aware but cannot appreciate the nature of his conduct, he will be exempted from punishment. And if the perpetrator still can appreciate the nature of his conduct, he must be punished for that offense, but the court may reduce the punishment less than what the law specifies for that offense at any time according to Section 65. Mostly, in cases where the court decides that the defendant is not guilty, the reason would be based on the provisions of Section 59, assuming that the offender is not conscious, for example, the Supreme Court Judgment No. 8743/2001, No. 2590/2019. However, in case that the offenders are mentally defective, mentally ill, or mentally deranged have committed an offense without knowing the “condition” and “essence” of the act, a separate provisions should be made to ensure that the person is not guilty and if the results of committing an offense is serious to life, body or property of another person, it should be at the discretion of the court to order that person to be sent for treatment in a hospital, similarly to what is provided in Section 48. In addition, if the offender can appreciate the nature of his conduct, or are still able to control themselves, there should be a criterion for reducing the punishment based on the seriousness of the offense, such as the criteria in the French Criminal Code to ensure fairness to the victims. Moreover, the method of probation should be applied after the defendant is released from prison in cases where he or she has committed a serious offense, as in France and England to prevent the offender from committing the crime again.