A couple of days ago I blogged about the flies, maggots and mould lurking in my green bin. Although maggots are icky they have an important role to play in medicine and murder. If you have ever wondered how forensic scientists can guess how long ago someone was murdered, maggots have the answer. Studying the size and age of maggots infesting a corpse can provide a strikingly accurate indication of the time and place of death.
Anyone who watches the hit TV show CSI may know there are three main area of forensics; chemistry, which is connected to crimes against property, such as burglary and arson; biology, which is connected to crimes against people, such as murder, assault and rape and drugs; and toxicology which determines drugs and poisons. Forensic entomology studies insects to provide clues for a murder.
Blowfly larvae are the insects most commonly associated with corpses and can colonise a body quickly after death. Blowflies have a keen sense for the stench of a decaying corpse. A body can start getting pungent within a few hours of death which lures the flies to feast off the rotting flesh and stash their eggs which will turn into maggots.
Egg laying is a key clue to where a murder may have taken place. At the crime scene a forensic entomologist will assess the likelihood of flies loitering at the location where the body was discovered. If this is unlikely, the flies may have begun to infest the body in another location.
Body temperature is also taken into consideration by forensics. Maggots develop slower at lower temperatures and fatten up rapidly in hot conditions. The location of the maggots on a body can also reveal important information. On an uninjured body, blowfly eggs are normally deposited on body orifices, and it is in these areas which maggots will start to feed first. If larger maggots are feeding from wounds this may indicate that the injuries took place before the death.
Entomological evidence was first used to convict a murderer in September 1935. Over 70 bodies parts were found wrapped in newspaper and dumped in a ravine in Dumfriesshire, Scotland. Forensic entomologist pioneer Dr A.G.Mearns examined the body parts which had attracted a fearsome bluebottle infestation. He dated the maggots to be around 12-14 days old.
The police had other two other clues to the murder. The newspapers used to wrap the body parts were limited editions only sold in Morecombe and Lancaster, 100 miles away. The second clue was that a driver nearly knocked a man off his bicycle in Kendal and he noted down the license plate. The maggot timeframe glued the clues together and led the police to a Dr Buck Ruxton of Lancaster. His wife and maid were missing and there was a suspicious bonfire in the garden. The locals gossiped that Dr Ruxton was a jealous husband with a furious temper. Dr Ruxton was found guilty of strangling his wife with his bare hands and suffocating the maid. He then mutilated the bodies and removed any identifying marks such as scars and finger tips. He was found guilty of the murders and hanged at Strangeways prison in Manchester. No doubt the maggots got him too in the end.