The Frequency of Truly Unknown/Undetermined Deaths: A Review of 452 Cases Over a 5-Year Period

The forensic autopsy is often regarded as the final medical diagnosis and expert scientific opinion in matters of death investigation, usually in the legal setting, and sometimes in the clinical setting as well. There are however limitations to what the autopsy can answer, and sometimes the circumstances surrounding a death, despite our best efforts, are simply unable to be determined. Approximately 5% of cases reportedly remain unknown after a complete autopsy. With this in mind, we sought to examine the frequency of deaths in which both the cause and manner are unknown after complete forensic examination and autopsy. Data from 452 undetermined deaths over a 5-year period were analyzed; sudden unexpected infant deaths and decomposed or skeletonized remains were excluded, as well as those with a known cause but undetermined manner of death. After exclusion of these deaths, our analysis revealed that only 0.015% of cases during this period were truly undetermined in both cause and manner of death.