Part 2Criminal offences
Chapter 1Murder, infanticide and suicide
Partial defence to murder: diminished responsibility
I152Persons suffering from diminished responsibility (England and Wales)
1
In section 2 of the Homicide Act 1957 (c. 11) (persons suffering from diminished responsibility), 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 medical 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 judgment;
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.
2
In section 6 of the Criminal Procedure (Insanity) Act 1964 (c. 84)
(evidence by prosecution of insanity or diminished responsibility), in paragraph (b) for “mind” substitute “
mental functioning
”
.
I253Persons suffering from diminished responsibility (Northern Ireland)
1
Section 5 of the Criminal Justice Act (Northern Ireland) 1966 (c. 20) (effect, in cases of homicide, of impaired mental responsibility) is amended as follows.
2
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 judgment;
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.
3
In subsection (2), for “subsection (1)” substitute “
subsection (1C)
”
.
4
In subsections (4) and (5), for “mental abnormality” substitute “
abnormality of mental functioning
”
.