Euthanasia is commonly referred to as 'mercy killing' and came to prominence in the South Australian case of R v. Johnstone (1987) 45 SASR 482; 137 LSJS 290. Active euthanasia is the term used when death is quickly and deliberately caused - for example, when an overdose of drugs is deliberately taken or administered. Passive euthanasia is the term used when death is caused by withholding or withdrawing treatment that merely sustains life; for example, removing life support systems from someone in a coma, see Care when dying. With passive euthanasia, death is technically from 'natural causes'.
The law relating to euthanasia in South Australia comes under the Criminal Law Consolidation Act 1935 (SA) [s 11]. Under this Act, death through active euthanasia is murder. As death by passive euthanasia is from 'natural causes', a doctor who withholds medical support with or without the consent of the patient or their representative (see Care when dying) is not said to have caused death. The Act does not relieve a medical practitioner from the consequences of a negligent decision as to whether or not the patient is suffering from a terminal illness.