Wednesday, July 6

Analyzing insects to solve police cases: this is how forensic entomology works

Entomology is the science that studies insects and other arthropods and can have a marked applied character, with forestry, medical, veterinary or forensic applications. This last specialty deals with the study of insects and other arthropods as biological evidence in legal matters, especially in cases that reach a court of law. Daniel Martín Vega is an entomologist, professor of the UAH Department of Life Sciences and collaborate with him UAH University Institute for Police Science Research. He tells us how the insects act as detectives helping the police to decipher murders, among other cases.

What is forensic entomology?

It is to apply the knowledge of the biology and development of insects and other arthropods, for example, mites, in legal, police and judicial investigations to obtain some type of information.

The most frequent application occurs when studying a case of death in suspicious circumstances and it is necessary to know the estimated date of death. In addition, forensic entomology is also used in any police or judicial investigation that involves the study of arthropods, such as investigations of food, product, or building infestations.

For example, if you know at what rate a type of insects develop, you will know their age, and thus you can estimate the date on which the infestation began to know if it occurred in the factory, in the warehouse or in the supermarket where you bought it. In the case of a corpse, knowing when the insects arrived can estimate the date of death.

Since when is this discipline used in police investigations?

Forensic entomology begins in the 19th century when the first treatise was published in France, previously it had been used in anecdotal cases. It is from the 80s when he began to investigate more actively and develop the discipline. But, like many other forensic disciplines, it was in the 2000s, with the rise of television series such as CSI, when it began to be taken more seriously in different institutions and laboratories.

There is a professional association in Europe and another in North America and, in Spain, forensic entomology has been used in different police cases and in institutions such as the National Institute of Toxicology and Forensic Sciences.

What are the first insects to reach a corpse?

Flies in the vast majority of cases. In forensic entomology, the most important insects are flies and beetles, and occasionally some wasps. Flies are able to locate a corpse shortly after death, they are even able to locate it in closed places, although in that case it may take them longer to access and colonize it. The species of beetles of greater forensic relevance are usually associated already with corpses in which skeletal remains, skin or cartilage remain.

Can insects give information about the causes of death?

Only in very specific cases. For example, there is a branch of forensic entomology called forensic entomotoxicology that helps in specific cases in which a toxicological examination of the tissues of the corpse cannot be carried out, for example, in bodies with an advanced state of decomposition, but nevertheless it can you can analyze the insects that have fed on these tissues and determine the presence of toxins, drugs, poisons …

Do you know any curious case that has been solved thanks to entomology?

There is a famous case that occurred in the United Kingdom at the beginning of the last century in which a doctor murdered his wife and her assistant and, although forensic sciences were not very developed, very new techniques were applied and used.

The corpses appeared in a river in Scotland, but in them they found quite developed larvae of flies, so it was deduced that they had not drowned, but that the bodies had to have been previously in a place where they had been colonized by flies and later they were thrown into the water. It is a very specific case where the presence of insects indicates the transfer of the corpse.

What do you have to study to be an entomologist?

It is necessary to train in biology, specialize in zoology and, more specifically, in the study of insects and other arthropods. In addition, if you are interested in forensic entomology and other scientific disciplines within criminology, you can develop your career with the State security forces, at the National Institute of Toxicology. Furthermore, in some countries private forensic services are also used.