- It is not a specific charge in itself but rather arises from a charge of murder to which a special and partial defence has been pleaded.
- They are called special since they may only be pleaded in defence to murder and partial because if successful results not in acquittal but in a conviction for manslaughter.
- This allows the judge to exercise discretion in choosing the appropriate sentence.
- D does not have the mens rea for murder
- 'the unlawful killing of a human being under the Queen's Peace without malice aforethought'
- Developed through common law
- The maximum sentence is life imprisonment, the judge has discretion, so may even pass a non-custodial sentence.