Most people blanch at even the thought of maggots, because of their association with decaying vegetation, flesh or manure. However, maggots certainly have their uses. They can be used to clean wounds, but one of the most amazing advantages that they have is that they can be used to determine the time of death, thereby allowing investigators to narrow down the list of suspects.
According to whatcom.wsu.edu, the type of maggot most likely to be found in people’s homes is the calliphorid maggot, which is the larva of the blow fly or bottle fly. However, there are a number of other types of maggots. Adult flies lay their eggs on or near rotting substances. The eggs then hatch very quickly and then feed on the decay around them. Mature maggots, just before they pupate, can be about half an inch in length.
This unfortunate habit of maggots liking rotting flesh is extremely useful for forensic entomologists, the name given to those scientists who study the use of “insects, and their arthropod relatives that inhabit decomposing remains to aid legal investigations.” However, as forensicentomology.com explains, the evidence that forensic entomologists track down isn’t just connected with murder – insect patterns can also be used as evidence in cases of abuse, automobile accidents and blood spatter analysis.
In the case of murder, maggots can actually turn witness. In the LA Times, one forensic entomologist, Dr Bernard Greenberg, described the assistance he was able to give to a double murder case back in the 1970s. The murders had been committed three years before, but there had been difficulty in tracking down the killer, simply because the time of death was dubious. Greenberg, simply by looking at morgue photos of maggots, and by factoring in the temperature for the time period the bodies were found, was able to determine the date of death to within two days. This evidence eventually led to a conviction.
A recent article in the Malaysian newspaper, The Sun Daily, describes a more updated process that forensic entomologists use to determine the time of death: “The maggots (and sometimes pupa) are first coated with a chemical and preserved in a bottle of liquid containing 80% alcohol (or ethanol). It takes about a week to determine the age of the maggots.” Once that has been done, experts can work backwards to determine approximately when the victim would have died.
The article goes on to say that, even more amazingly, the type of maggots found on the body can help experts narrow down the location of death. For example, some types of maggots, such as calliphorid maggots, are primarily found in people’s houses. Others are only found near water, or in hilly areas. Forensicentomology.com explains that this can also be used to prove that a body was moved after death. For example, if the body was discovered indoors, but it contained maggots only found in sunny areas, would suggest that someone had returned to the scene of crime after the maggots had time to take hold and moved the body.
Criminals know that they need to keep on top of scientific advances in crime detection. Fortunately, there is little that they can do to control nature and, as long as there are flies, maggots will continue to bear witness to murder.