Voluntary manslaughter - diminished responsibility
Section 2 of the Homicide Act 1957, as amended by section 52 of the Coroners and Justice
Act 2009.
Burden of Proof
When the defence wants to rely on using ‘diminished responsibility’, it is the defendant that
has the burden to show there is some medical reason for acting the way that they did (S.2 of
the Homicide Act 1957).
The defence only needs to prove this on the balance of probabilities.
For subsection (1) substitute—
“(1) A person (“D”) who kills or is a party to the killing of another is not to be convicted of
murder if D was suffering from an abnormality of mental functioning which—
(a) arose from a recognised mental condition,
(b) substantially impaired D's ability to do one or more of the things mentioned in
subsection (1A), and
(c) provides an explanation for D's acts and omissions in doing or being a party to the
killing.
(1A) Those things are—
(a) to understand the nature of D's conduct;
(b) to form a rational judgement;
(c) to exercise self-control.
(1B) For the purposes of subsection (1)(c), an abnormality of mental functioning provides an
explanation for D's conduct if it causes, or is a significant contributory factor in causing, D to
carry out that conduct.
(1C) Where, but for this section, D would be liable, whether as principal or as accessory, to
be convicted of murder, D is liable instead to be convicted of manslaughter.”
Abnormality of Mental Functioning
- The defendant’s state of mind must be so different from an ordinary human being
that the ‘reasonable person’ would term it as abnormal.
- This includes the mind’s ability to exercise will power to control actions.
R v Byrne
The appellant murdered a young girl staying in a YWCA hostel. He then mutilated her body.
He did so as he was suffering from irresistible impulses which he was unable to control.
It was held that "abnormality of mind" was wide enough to cover the mind's activities in all its
aspects, including the ability to exercise will power to control physical acts in accordance
with rational judgement. But "abnormality of mind" means a state of mind so different from
that of ordinary human beings that a reasonable man would term it abnormal. He was thus
allowed the defence to reduce the murder conviction to manslaughter.
Section 2 of the Homicide Act 1957, as amended by section 52 of the Coroners and Justice
Act 2009.
Burden of Proof
When the defence wants to rely on using ‘diminished responsibility’, it is the defendant that
has the burden to show there is some medical reason for acting the way that they did (S.2 of
the Homicide Act 1957).
The defence only needs to prove this on the balance of probabilities.
For subsection (1) substitute—
“(1) A person (“D”) who kills or is a party to the killing of another is not to be convicted of
murder if D was suffering from an abnormality of mental functioning which—
(a) arose from a recognised mental condition,
(b) substantially impaired D's ability to do one or more of the things mentioned in
subsection (1A), and
(c) provides an explanation for D's acts and omissions in doing or being a party to the
killing.
(1A) Those things are—
(a) to understand the nature of D's conduct;
(b) to form a rational judgement;
(c) to exercise self-control.
(1B) For the purposes of subsection (1)(c), an abnormality of mental functioning provides an
explanation for D's conduct if it causes, or is a significant contributory factor in causing, D to
carry out that conduct.
(1C) Where, but for this section, D would be liable, whether as principal or as accessory, to
be convicted of murder, D is liable instead to be convicted of manslaughter.”
Abnormality of Mental Functioning
- The defendant’s state of mind must be so different from an ordinary human being
that the ‘reasonable person’ would term it as abnormal.
- This includes the mind’s ability to exercise will power to control actions.
R v Byrne
The appellant murdered a young girl staying in a YWCA hostel. He then mutilated her body.
He did so as he was suffering from irresistible impulses which he was unable to control.
It was held that "abnormality of mind" was wide enough to cover the mind's activities in all its
aspects, including the ability to exercise will power to control physical acts in accordance
with rational judgement. But "abnormality of mind" means a state of mind so different from
that of ordinary human beings that a reasonable man would term it abnormal. He was thus
allowed the defence to reduce the murder conviction to manslaughter.
