There is little doubt that provision of estimates of Post Mortem Interval (PMI) in the latter period (i.e. beyond that time traditionally estimated by pathologists) provides key support to public service and legal representation. Forensic Entomology is one way to assess this decomposition period or ‘window of opportunity’.The Sherlock’s Window project forms a cornerstone to academic understanding of Post Mortem Interval in light of the many obstacles PMI currently encounters, and beyond which its successful application to crime scene analysis will elevate entomological techniques to produce evidence suited to courtroom delivery. By providing insight into a new and hopefully more accurate technique of devising PMI estimates, it is thought that this project will enhance legal representation and further help to resolve fatal crimes.At present the use of blowflies in Forensic Entomology for the estimation of Post Mortem Interval is confounded by numerous variables often of no measurable or known effect. The proposed research aims to work around these many variables and provide crime scene investigators worldwide with a new and more precise measure of maggot identity and age, leading to more accurate estimations of time of death. This may have a profound impact on the way Forensic Entomology interacts with the legal infrastructure and will certainly impact on forensic education which is currently dominated by established techniques which are subject to huge variation and frequently leave students bewildered and confused. Such confusion is equally apparent within the legal context when PMI evidence is presented in court. Not only will the new technique bring clarity to the estimation of Post Mortem Interval , but it is hoped that by being quantifiable, it will enhance the delivery of Forensic Entomological evidence in court as well as elevate confidence in Post Mortem estimation.
Many techniques used by Forensic Entomologists rest on mathematical modelling constructed on fixed temperature laboratory cultures of flies, from which various growth analyses are derived. Extensive human tissue restrictions, in place in most countries, prevent research on human tissue. As a consequence, alternative culture media are used, the most readily accepted of which for courtroom evidence is pork because of many similarities to human tissue. Increasingly, the use of such analogues can result in a mismatch between courtroom expectations and actual data, especially when pork is replaced with another type of carcass.The initial research focus will be on producing an improved standard operating protocol for rearing blowfly larvae in culture using an artificial odourless diet that can be replicated in any laboratory across the world. The aim here is to provide a ‘benchmark’ standard against which to measure growth rates in each species of blowfly significant to crime scene analysis, thereby bringing equivalence into the legal process of PMI estimation. Furthermore, using novel techniques, we aim to deliver more accurate identification and ageing of blowfly larvae seized from decomposing remains at crime scenes and at autopsy.
Bournemouth University's Research Blog: Sherlock’s Window: In search of an odourless growth mediumA rare insight into the fly ages of Sherlock’s Window