The Defendant's Conduct

The Defendant's Conduct 

The prosecution must prove that the defendant's act or omission was a "substantial cause" of death, though it need not be the sole or main cause; it is enough that the act or omission was "more than minimal" and significantly contributed to the death. Murder involves the defendant's conduct accelerating the victim's death. As a general rule, criminal liability is founded on an "act" (that is, a positive act). An "omission" (that is, a failure to act) will give rise to criminal liability only where the defendant is under a legal duty to act. 

The conduct constituting murder may take the form of directly inflicting physical violence on the deceased, but it may also take other forms, for example: 

• where a person who owes a duty of care to another who is incapacitated by age or some other cause deliberately places that person in a cold environment, exposes him to the elements, or confines him in circumstances sufficient to be fatal, leaving him to die of starvation, this may amount to murder; 
• bringing about a fatal outcome through a particular arrangement (for example, placing a spherical yoga ball that releases carbon monoxide at the scene, ultimately causing death); 
• commission through an innocent agent, that is, where the perpetrator uses a wholly unwitting person to carry out the fatal act. For example, if poison is given to A, who then mistakenly administers it to B and thereby causes B's death, liability still rests with the person who originally supplied the poison. 

Although every murder is one of "accelerating death", the House of Lords has held that, where a patient is unable to decide for himself whether to consent to treatment, a doctor who, in his professional judgment, considers that continuing invasive life-sustaining treatment is not in the patient's best interests may, in certain circumstances, lawfully withdraw treatment and allow the patient to die naturally, and this may be regarded as a lawful medical decision.