A Forensic Entomologist (FE) can contribute to a death investigation, usually by helping to estimate the time of death, or postmortem interval (PMI). To do this the FE makes use of two insect-based postmortem clocks. The first is the development of an insect thought to have fed on the corpse all of its life. A development analysis may yield an estimate of minimum PMI (PMImin), or “Dead for not less than a given amount of time.” The second is the succession of insect’s species that takes place over time following death. A succession analysis may yield the actual PMI. Accurate FE analysis depends on correctly identifying the insect(s), reconstructing the corpse environment prior to evidence collection, and the availability of suitable reference data. Among the most important factors influencing insect development and succession rate is temperature and the intrinsic differences between the insect species. Hundreds of insect’s species may be observed on a human corpse, but most FE analyses use a small number of fly and beetle species. Most commonly used are the blow flies (Calliphoridae) and flesh flies (Sarcophagidae) the larvae of which, called maggots, feed on carrion.
