It is argued by some that the way in which Scots criminal law draws the distinction between murder and culpable homicide is unsatisfactory. Some say that the scope of murder is too narrow and that the scope of culpable homicide is too wide. It is necessary to discuss how the crimes of murder and culpable homicide are treated in Scots law, by analysing how the law is applied in cases involving murder and culpable homicide.
Macdonald states “murder is constituted by any wilful act causing the destruction of life, whether intended to kill, or displaying such wicked recklessness as to imply a disposition depraved enough to be regardless of consequences”.1 Two kinds of mens rea are sufficient for murder: intention to kill and wicked recklessness.
It is widely accepted that for wicked recklessness to be fulfilled there must be intention to cause injury as well as a wicked disregard of or indifference to possible fatal consequences. In Halliday v HM Advocate2, A and P were charged with murder. Following a scuffle with A and P the deceased had fallen on the ground, whereupon he was kicked and punched until he lay motionless. A and P were then seen to shake hands, say that they were great brothers and return to the deceased, kicking him in the face and stamping on his head. After being told to stop, A and P placed the deceased in the recovery position and returned to their house where they attempted to wash their clothes. Later A and P returned to the scene and called for an ambulance.
In HM Advocate v Purcell3 an accused person was charged with murdering a 10 year old boy whom he hit with his motor vehicle while being pursued by police officers. It was not alleged that the accused had intended to cause injury to any person. The accused submitted that common law reckless or dangerous driving resulting in death constituted at most culpable homicide. It was agreed that submissions on that matter should be heard by a bench of three judges. The accused’s submissions were upheld, that the modern law was that there was murder wherever death was caused with wicked intention to kill or by an act intended to cause physical injury and displaying a wicked disregard of fatal consequences. The terms of the indictment did not allege any intentional crime of assault or the commission of other personal injury and thus did not support a charge of murder.
Some may argue that the scope of murder is very narrow

Culpable homicide refers to the various types of unlawful killings where the accused’s culpability is less than that required for murder. Macdonald states “culpable homicide is the name applied to cases where death is caused by improper conduct and where the guilt is less than murder”4.
In Galbraith v HM Advocate5 G appealed against her conviction for the murder of her husband on the ground of misdirection. During her trial, G claimed to have been subjected to abuse by the deceased for some years, and in support of a plea of diminished responsibility, she led evidence from two psychologists that she had been suffering from a form of post-traumatic stress disorder. The appeal was allowed, and it was established that diminished responsibility required some form of abnormality of the mind sufficient to have a substantial effect on a person’s mind and in relation to his act, but it was not necessary to prove that the accused’s mental state bordered on insanity and such a test should not be referred to except where a real question arose as to whether the accused was insane at the time. It was also stated that the abnormality may take various forms, it had to be one that was recognised by the appropriate science, but it might be congenital or derive from an organic condition, from some psychotic illness or from the psychological effects of severe trauma.
Previously, diminished responsibility referred to substantial mental impairment of an accused’s ability to determine and control his acts and emissions due to mental abnormalities6. Since the