[5] Some jurisdictions require the evaluation to address the defendant's ability to control their behavior at the time of the offense (the volitional limb).
The term may be applied when a determination of competency needs to be made by a physician for purposes of obtaining informed consent for treatments and, if necessary, assigning a surrogate to make health care decisions.
[7] In English law, the rule of non compos mentis was most commonly used when the defendant invoked religious or magical explanations for behaviour.
[9] However, in colonial America a delusional Dorothy Talbye was hanged in 1638 for murdering her daughter, as at the time Massachusetts's common law made no distinction between insanity (or mental illness) and criminal behavior.
[10] Edward II, under English common law, declared that a person was insane if their mental capacity was no more than that of a "wild beast" (in the sense of a dumb animal, rather than being frenzied).
When that was replaced by trial by jury, members were expected to find the insane guilty but then to refer the case to the king for a royal pardon.
[11] The Criminal Lunatics Act 1800, passed with retrospective effect following the acquittal of James Hadfield, mandated detention at the regent's pleasure (indefinitely) even for those who, although insane at the time of the offence, were now sane.
[22] The United States Supreme Court (in Penry v. Lynaugh) and the United States Court of Appeals for the Fifth Circuit (in Bigby v. Dretke) have been clear in their decisions that jury instructions in death penalty cases that do not ask about mitigating factors regarding the defendant's mental health violate the defendant's Eighth Amendment rights, saying that the jury is to be instructed to consider mitigating factors when answering unrelated questions.
The Homicide Act 1957 is the statutory basis for the defense of diminished responsibility in England and Wales, whereas in Scotland it is a product of case law.
[29][30] Unlike defendants who are found guilty of a crime, they are not institutionalized for a fixed period, but rather held in the institution until they are determined not to be a threat.
[39] In Woodbridge v The Queen the court stated that a symptom indicating a disease of the mind must be prone to recur and be the result of an underlying pathological infirmity.
[43] The defence of mental disorder is codified in section 16 of the Criminal Code which states, in part: To establish a claim of mental disorder the party raising the issue must show on a balance of probabilities first that the person who committed the act was suffering from a "disease of the mind", and second, that at the time of the offence they were either 1) unable to appreciate the "nature and quality" of the act, or 2) did not know it was "wrong".
While proceedings before a Review Board are less formal than in court, there are many procedural safeguards available to the accused given the potential indefinite nature of Part XX.1.
However, in R. v. Demers, the Supreme Court of Canada struck down the provision restricting the availability of an absolute discharge to an accused person who is deemed both "permanently unfit" and not a significant threat to the safety of the public.
Presently a Review Board may recommend a judicial stay of proceedings in the event that it finds the accused both "permanently unfit" and non-dangerous.
In Denmark a psychotic person who commits a criminal defense is declared guilty but is sentenced to mandatory treatment instead of prison.
The offender receives no judicial punishment; they become a patient under the jurisdiction of THL, and must be released immediately once the conditions of involuntary commitment are no longer fulfilled.
[citation needed] Section 39 of the Dutch criminal code stipulates: "Not culpable is he who performs an act that he cannot be imputed with due to the deficient development or pathological disorder of his mental faculties".
The result of the forensic examination is then subjected to a legal assessment, taking into account other circumstances of the case, from which a conclusion is drawn about the defendant's sanity or insanity.
The Criminal Code of Russia establishes that a person who during the commission of an illegal act was in a state of insanity, that is, could not be aware of the actual nature and social danger of their actions or was unable to control them due to a chronic mental disorder, a temporary mental disorder, or dementia is not subject to criminal liability.
I say, where the insanity is absolute, and is duly proved: For if reason and humanity enforce the plea in these circumstances, it is no less necessary to observe a caution and reserve in applying the law, as shall hinder it from being understood, that there is any privilege in a case of mere weakness of intellect, or a strange and moody humor, or a crazy and capricious or irritable temper.
To serve the purpose of a defense in law, the disorder must therefore amount to an absolute alienation of reason, ut continua mentis alienatione, omni intellectu careat – such a disease as deprives the patient of the knowledge of the true aspect and position of things about them - hinders them from distinguishing friend from foe – and gives them up to the impulse of their own distempered fancy.The phrase "absolute alienation of reason" is still regarded as at the core of the defense in the modern law (see HM Advocate v Kidd (1960) JC 61 and Brennan v HM Advocate (1977) In the United States, variances in the insanity defense between states, and in the federal court system, are attributable to differences with respect to three key issues: In Foucha v. Louisiana (1992) the Supreme Court of the United States ruled that a person could not be held "indefinitely" for psychiatric treatment following a finding of not guilty by reason of insanity.
In Kahler v. Kansas (2020), the U.S. Supreme Court held, in a 6–3 ruling, that a state does not violate the Due Process Clause by abolishing an insanity defense based on a defendant's incapacity to distinguish right from wrong.
The Court emphasized that state governments have broad discretion to choose laws defining "the precise relationship between criminal culpability and mental illness.
[56] The House of Lords asked the judges of the common law courts to answer five questions on insanity as a criminal defence,[57][58] and the formulation that emerged from their review—that a defendant should not be held responsible for their actions only if, as a result of their mental disease or defect, they (i) did not know that their act would be wrong; or (ii) did not understand the nature and quality of their actions—became the basis of the law governing legal responsibility in cases of insanity in England.
[12] It was first used as a defense in the United States in the case of People v. Freeman in 1847, where an Afro-Native man from Auburn, New York was tried for a quadruple murder.
The test has more lenient guidelines for the insanity defense, but it addressed the issue of convicting mentally ill defendants, which was allowed under the M'Naghten Rule.
Under this new test only perpetrators suffering from severe mental illnesses at the time of the crime could successfully employ the insanity defense.
The Act also curbed the scope of expert psychiatric testimony and adopted stricter procedures regarding the hospitalization and release of those found not guilty by reason of insanity.
In 2001, the Nevada Supreme Court found that their state's abolition of the defense was unconstitutional as a violation of Federal due process.