The larval stage has three distinct substages, instars, and because we know how long each stage lasts, the presence of any stage can be used to date the arrival of the colonising fly. Blowflies undergo metamorphosis and their life cycle has four stages egg, larva (maggot), pupa and adult. They may arrive within minutes of death and deposit maggots (in the case of flesh-flies) or lay their eggs (blowflies) in wounds or in the mouth, eyes or nostrils houseflies arrive a little later. The first insects to colonise an above-ground body are true flies (order Diptera). Imagine a scenario whereby a dead body has been discovered in a wood - one way of estimating how long it has been there is to identify the insects that have colonised it. I also make reference to a number of high profile cases involving fire investigations.įorensic entomology involves the application of insect and other arthropod biology in legal investigations. In this podcast, I explore how cases of arson are determined, the motivating factors for someone to commit such an attack and what fire patters can reveal to the trained eye. Investigations are compromised, and often scenes are further destroyed by the activities of the fire service, whose primary responsibilities are to save lives and protect property against further damage. Fires, by their destructive nature, consume the evidence of their initiation and progress as they grow. Insensibly, one begins to twist facts to suit theories instead of theories to suit facts.' As Holmes pointed out, many types of investigations are susceptible to prejudgment, but few as often as fire scene investigations. Arthur Conan Doyle’s literary detective Sherlock Holmes is quoted as saying, 'It is a capital mistake to theorise before one has data. Careful, thorough investigation is key to ensuring that potential physical evidence is not tainted or destroyed, or potential witnesses overlooked. (With thanks to our sponsor 'Curriculum Press' for providing content for this podcast)Īctions taken at the outset of an investigation at a fire and arson scene can play a pivotal role in the resolution of a case.
Nonetheless, it is unlikely that research will give us a full understanding of NDEs and, even if it did, it is unlikely that everyone would accept these insights whatever causes NDEs, the effect of having one seems to be highly profound, meaning people are likely to formulate their own explanations of what they experienced in order to draw meaning from their own vivid experience. However, by using a mixture of different methods which explore real-life experiences as well as laboratory-induced ones, it becomes possible to triangulate these findings in order to increase our understanding. Even here though, the researchers are still not able to directly experience the NDE for the participant. Some researchers have tried to address this by artificially simulating NDEs in laboratories, using drugs. This is partly because researchers are entirely dependent on the reports people provide of their individual experience, which means the data is received second-hand and there is no way of verifying that the report given is accurate. There will always be elements of near death experiences (NDE's) that are difficult to explain scientifically.