New insect database to help with forensic investigations Image By Kajano AdobeStock_54787347 copy

Cranfield University database thought to be the first of its kind

Cranfield University researchers are using blowflies and other insects to develop a database which will provide a complementary method of estimating time since death in forensic investigations.

The database is thought to be the first of its kind in the world. It uses chemical profiles from the insects’ waxy coating and will provide a library for forensic entomologists to refer to when investigating cases.

Forensic pathologists can give an accurate post-mortem interval estimate up to 72 hours after death. After this, forensic entomologists are often called to crime scenes and use the age of insects that inhabit decomposing remains to give a more accurate indication of how long the person has been deceased.

Dr Hannah Moore Image: Cranfield University
Dr Hannah Moore, lecturer at Cranfield Forensic Institute (CFI), said:

“Knowing how long someone has been dead, particularly in the case of murder, is vital in proving the innocence or guilt of suspects.

“Insects can also tell us if the person consumed drugs, if their body was moved or whether it has been frozen – they’re the most reliable witnesses in many cases.”

The most established way to estimate the age of insects is to use their length, as well as other variables. But these are influenced by the temperature of an environment. The database at Cranfield uses cuticular hydrocarbons (CHC). These are a class of compounds found in the epicuticular layer which covers insects.

“These compounds act like a fingerprint and are species-specific. This provides a complementary method of identifying and ageing insects which has proved extremely accurate.

“The robustness of this method may be useful in court cases for presenting reliable and clear-cut evidence in the future.”

The project will also examine geographical differences within the same species across different climates to model the stability of the CHC samples, which are taken from the larvae of the insects.

It is estimated that the database will take five years to complete. It will include all forensically important species, with a focus on blowflies.