Abstract
This article discusses the importance of forensic entomology in investigating crimes. This also explains how insect species, such as Diptera, found on or near a dead body or carcass can provide essential information and evidence for crime scene reconstruction.
This article also focuses on how insects help determine the time of death, identify the cause, and verify the deceased’s location. The article also highlights the role of Diptera in forensic science and how they can provide useful insights for estimating the post-mortem interval, pointing out whether a body was moved or disturbed after dying, and can also indicate the victim’s intake of drugs or poisons.
Introduction
Forensic entomology is a field that studies arthropod species found on a dead body or near it for crime scene reconstruction, dating the time of the death of the subject and identifying the cause of death and the perpetrator. Insect species, collected on and around the body, represent useful evidence for criminal investigation. Forensic entomology applies to both crimes against humans and domestic or wild animals.
During the forensic examination, the entomologist has to examine the crime scene, the environmental context, the location and condition of the body, the presence of fauna, both before and after the removal of the corpse, and measure the environmental temperature at the time of the inspection. Therefore, the entomologist must estimate the time of death of a subject and verify whether the location of the discovery of the corpse coincides with that where the death occurred.
Decomposition
Role of Diptera
Diptera play a crucial role in forensic science because they provide a range of important information, including:
- They provide helpful information for estimating the post-mortem interval (IPM), a principal element that the forensic entomologist can often define.
- Insects indicate whether the body was moved or disturbed after death and, therefore, whether the place of discovery coincides with where death occurred. The entomologist assesses whether a body has been moved to a secondary crime scene by the presence or absence of certain insect species related to a specific habitat type.
- Insects provide information about the presence of wounds by following the atypical distribution pattern of larval masses. Typically, larvae initially colonize natural body cavities, such as the mouth, eyes, and anus. Still, if bloody wounds are present, these are more attractive and are the preferred site of Ovi deposition.
- Insects provide information about the victim’s intake of drugs or poisons. This is possible through analysis of the stomach contents of larvae and/or adults, which absorb all substances in the corpse by feeding on the body tissues. Entomotoxicology is that discipline that, through chemical analysis, searches for drugs and toxins in insects to determine the causes of death of individuals found dead if direct investigation of the remains is not possible.
- Diptera are indicators in cases of neglect or abuse of elderly people, children, and animals in life. Therefore, they also play an important role in assessing the condition of the ante-mortem life of a subject. Insects that cause “miasigenic pictures” are important in forensic entomology because their presence on a living human body is often synonymous with hygienic problems and neglect.
Role of Diptera in Post-Mortem Interval
The post-mortem interval (PMI) refers to the time between death and the discovery of a dead body. Usually, the first taxa to arrive after death are flies, especially the Diptera Calliphoridae, which can locate a corpse and lay their eggs within minutes of death.
Due to the presence of insects, particularly fly larvae, it is possible to calculate the colonization time, which indicates a minimum PMI, that is, the time when the arthropods first colonized the body, which could coincide with the actual time of death.
The key element is that the development time of fly larvae depends on the temperature to which they are subjected during growth. Thus, estimates of larval development concerning temperature are very useful in establishing a time range termed postmortem interval, helping to indicate when death might have occurred. When used in conjunction with other data, such as successional models or direct age classification of insect larvae, these estimates are important for crime scene reconstruction.
Conclusion
In conclusion, forensic entomology is vital in criminal investigations because it provides valuable evidence for determining the time since death. The presence of insects, particularly fly larvae, can help establish a time range termed the postmortem interval, which is important for crime scene reconstruction. Therefore, forensic entomology provides a valuable tool for law enforcement agencies and judicial systems worldwide in the pursuit of justice.
References
Importance of Calliphoridae Diptera in Forensic Science: Forensic’s Blog. https://forensicfield.blog/importance-of-calliphoridae-diptera-in-forensic-science/
Authored By
This article is written by Ms. Chiara Lucanto. She is a Forensic Biologist.
Mail: chia94lu@gmail.com
