|
In criminal trials, the insanity defense is the claim that the defendant is not responsible for his or her actions during a mental health episode (psychiatric illness or mental handicap). Exemption of the insane from full criminal punishment dates back to at least the Code of Hammurabi.〔Fletcher, G. (1998) Basic Concepts of Criminal Law. NY: Oxford Univ. Press.〕 There are different definitions of legal insanity, such as the ''M'Naghten Rules'', the Durham Rule, the American Legal Institute definition, and various miscellaneous provisions (e.g., relating to lack of mens rea). In the United Kingdom, Ireland, and the United States, use of the defense is rare; however, since the Criminal Procedure (Insanity and Unfitness to Plead) Act 1991, insanity pleas have steadily increased in the UK.〔RD Mackay, BJ Mitchell, L Howe (2006) 'Yet more facts about the insanity defence' ''Criminal Law Review'' 399-411〕 Mitigating factors, including things not eligible for the insanity defense like intoxication〔American Psychiatric Association: The Insanity Defense: Position Statement. Washington, DC: APA Document Reference No. 820002, 1982〕 (or, more frequently, diminished capacity), may lead to reduced charges or reduced sentences. The insanity defense is based on evaluations by forensic mental health professionals with the appropriate test according to the jurisdiction. Their testimony guides the jury, but they are not allowed to testify to the accused's criminal responsibility, as this is a matter for the jury to decide. Similarly, mental health practitioners are restrained from making a judgment on the issue of whether the defendant is or is not insane or what is known as the "ultimate issue". Some jurisdictions require the evaluation to address the defendant's ability to control their behavior at the time of the offense (the volitional limb). A defendant claiming insanity is pleading "not guilty by reason of insanity" (NGRI) or "guilty but insane or mentally ill" in some jurisdictions which, if successful, may result in the defendant being committed to a psychiatric facility for an indeterminate period. ==Mitigating factors and diminished capacity== 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. This ruling suggests specific explanations to the jury are necessary to weigh mitigating factors. Diminished responsibility or diminished capacity can be employed as a mitigating factor or partial defense to crimes and, in the United States, is applicable to more circumstances than the insanity defense. Where it is a partial defense, it has the effect of reducing the charge to manslaughter. The Homicide Act 1957 is the statutory basis for the defense of diminished responsibility in England & Wales, whereas in Scotland it is a product of case law. The number of findings of diminished responsibility has been matched by a fall in unfitness to plead and insanity findings (Walker, 1968). A plea of diminished capacity is different from a plea of insanity in that "reason of insanity" is a full defense while "diminished capacity" is merely a plea to a lesser crime. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Insanity defense」の詳細全文を読む スポンサード リンク
|