How the defence of diminished responsibility is different from the defence of insanity?

The defences of diminished responsibility and insanity are both legal defences that may be used in criminal trials where the accused is arguing that they were not fully responsible for their actions due to a mental disorder. While these defences may seem similar, they differ in several important ways.

Firstly, the defence of diminished responsibility is used to argue that the accused is guilty of the lesser offence of manslaughter rather than murder. In contrast, the defence of insanity is used to argue that the accused is not guilty of the crime at all.

Secondly, the two defences have different criteria that must be met in order to be successful. To argue diminished responsibility, the accused must show that they were suffering from an abnormality of mental functioning that substantially impaired their ability to understand the nature of their conduct, form a rational judgment, or exercise self-control. In contrast, to argue insanity, the accused must demonstrate that they were suffering from a mental disorder that substantially impaired their ability to understand the nature and quality of their actions, or understand that their actions were legally wrong.

Thirdly, the two defences may lead to different outcomes for the accused. If the defence of diminished responsibility is successful, the accused will still be found guilty of a criminal offence, but may receive a lesser sentence. If the defence of insanity is successful, the accused will be found not guilty by reason of insanity and may be detained in a psychiatric hospital or other institution for treatment.

Finally, the two defences have different implications for society and the criminal justice system. The defence of diminished responsibility is often used in cases where the accused has a recognised mental disorder, while the defence of insanity may be used in cases where the accused's mental state is more controversial or less clear-cut. This can lead to debate over the appropriate use of these defences and the implications for public safety and the treatment of individuals with mental disorders.

In summary, while both diminished responsibility and the insanity defence address the role of mental health in criminal liability, they serve different purposes and have distinct legal standards and outcomes.
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