The Cause, Mechanism, and Manner of Death
The most important function of the medical examiner in any death investigation is determining the cause, mechanism, and manner of death. Here are definitions of each of these terms:
Cause of death: The disease or trauma that directly caused the victim’s death. Examples include a heart attack, a gunshot wound to the head, or a drug overdose.
Mechanism of death: The specific physiological derangement that actually led to the cessation of life. For example, a heart attack victim could die from a deadly change in heart rhythm or from severe damage to the heart muscle, leading to shock. Here the cause of death is a heart attack, but the mechanism is a cardiac arrhythmia or cardiogenic shock, respectively.
Manner of death: How the cause of death came about. The five manners of death are natural, accidental, suicidal, homicidal, and undetermined. A gunshot wound (the cause of death), may have been accidental, suicidal, or homicidal, for example. Only deaths from disease are natural.