What is the physical change observed that indicates the need for an autopsy?

The presence of petechial hemorrhages is a significant physical change that often indicates the need for an autopsy. These small red or purple spots that appear on the skin are a result of bleeding underneath the skin's surface, which can point to various causes of death, including asphyxia, strangulation, or other forms of trauma. Their identification can provide crucial insights into the circumstances surrounding a death, particularly in cases that may be classified as suspicious or unexpected.

In contrast, visible bruising and rigor mortis can be normal findings in deceased individuals but do not necessarily warrant an autopsy unless accompanied by other indicators. Visible bruising may occur from natural causes or existing medical conditions, while rigor mortis is a natural post-mortem process that occurs as muscle fibers undergo chemical changes. Lastly, general post-mortem changes, which encompass a range of alterations after death, such as livor mortis and decomposition, also do not singularly indicate the need for an autopsy without further context suggesting foul play or unnatural causes.