This occurs when the person who dies wants to live but is killed anyway.
In involuntary euthanasia the person may be competent but have their views on the matter disregarded or overruled.
Notes:
Involuntary Euthanasia is usually the same thing as murder, however one could imagine some unusual cases where the killing would count as being for the benefit of the person who dies, a mercy killing.
Follow the BBC link below on "Examples of Involuntary Euthanasia" for examples.
Sources:
BBC. Religion & Ethics. Euthanasia. Key Terms. Available at: http://www.bbc.co.uk/religion/ethics/euthanasia/overview/keywords.shtml
BBC. Religion & Ethics. Euthanasia. Examples of Involuntary Euthanasia. Available at: http://www.bbc.co.uk/religion/ethics/euthanasia/overview/volinvol.shtml
DeSpelder LA. Strickland AL. 2005. The Last Dance: Encountering Death and Dying. 7th Edition. New York, N.Y.: McGraw Hill.
Garrard E, S Wilkinson S. Passive euthanasia. J Med Ethics 2005;31:64-68. Available at: http://jme.bmjjournals.com/cgi/content/full/31/2/64
The most notorious example of involuntary euthanasia is the medicalized killing programs of the Nazi regime.

