Practical Exercise in Forensic Entomology

• NCJ Number: 164894
• Journal: Gazette Volume: 58 Issue: 9 Dated: (September 1996) Pages: 3-6
• Author(s): G S Anderson
• Date Published: 1996
• Length: 4 pages
• Publication Format: Article
• Publication Type: Training (Aid/Material)
• Language: English
• Country: Canada

Annotation

Using actual cases, this article discusses how a study of insect activity on corpses and other crime-scene materials can yield valuable evidence, and a Canadian class exercise on this topic is described.

Abstract

In one case, insect evidence was collected from two homicide victims on the 17th of the month. Based on the insect life cycles, the date of death was determined to be the 6th of the month or earlier. Two witnesses claimed they had seen the victims murdered on the third of the month, but other witnesses claimed they saw one of the victims on the ninth. Based on the entomologist's report, the testimony of the latter witnesses was refuted, and the defendant was convicted. In another case, insect evidence placed the date of initial infestation of a human head on or before the date on which the victim's spouse was told insurance money could not be collected without proof of his wife's death. Date of death estimation is probably the most common and best-known use of forensic entomology in criminal investigations. If the death has occurred within a few weeks of the body being found, the entomologist will be able to estimate a date of death by using data on the life cycle of the species of fly larvae found on the body. Maggots can be collected and reared to adulthood in a laboratory setting, and then, using what is known about the length of time required for the particular species of fly to reach maturity, the entomologist can calculate backwards to when the first eggs were laid on the body. Analysis of maggots can also be used to show the presence of both legal and illegal drugs in the body. In cases of child or elder abuse, infested bed sores or diapers may be accompanied by the presence of insects. The entomologist may be called in to give an expert opinion as to how long the neglect may have occurred, depending on the insects' level of development. This article also describes the entomology session of a training course, which includes exposing students to insects in the decomposed body of a pig, so they may experience a low-pressure practice exercise that will prepare them for exposure to decomposing human remains at a crime scene.