Diminished Responsibility: When Can Murder Be Reduced To Manslaughter?

Diminished responsibility is one of the most complex and misunderstood defences in criminal law. Many people assume that a diagnosis of mental illness will automatically provide a defence to murder. In reality, the law sets a very high threshold, specialist psychiatric evidence is essential, and the burden of proving the defence rests with the defendant.

A recent case handled by Olliers highlights just how difficult it can be to establish diminished responsibility, even where there is a well-documented history of mental health difficulties.

What is diminished responsibility? 

Diminished responsibility is a partial defence to murder. If successfully established, it does not result in an acquittal. Instead, it reduces a conviction for murder to a conviction for manslaughter.