Review: Books On Forensic Science Essay, Research Paper
Body of evidence Fingerprints: Murder and the Race to Uncover the Science of Identity
243pp, Fourth Estate Time of Death: Forensic Science and the Search for Death’s Stopwatch
Jessica Snyder Sachs
288pp, Heinemann A Fly for the Prosecution: How Insect Evidence Helps Solve Crimes
M Lee Goff
240pp, Harvard Following on from TV and other media attention, this clutch of books shows what a hold forensics currently has on the public imagination. Our fascination with that archetypal science of identification – whose corpse is this? Whodunnit? – is simple to explain. Living as we do in a world of doubt and disinformation, the technical wizardry of forensic science holds out a rare promise of certainty: in moves the pathologist, and all is light. Thanks to genetics, for example, DNA testing can now leave courts absolutely positive, at least as to who could not possibly have committed a rape or fathered a child. In the days before forensic science, our forefathers might resort to what seem quite bizarre ways of establishing guilt in a crime: trial by ordeal, “swimming” a witch, or the belief that a corpse would bleed on the approach of a murderer. God, it was hoped, would intervene to expose the offender. With the waning of that age of faith, however, society was thrown back on eye-witness testimony, with all its imperfections: memories are notoriously untrustworthy, and mistaken identity all too common. That is why the advent of fingerprinting was such a turning point in the history of detection. At last there was objective evidence – the culprit had left his autograph at the scene of the crime. But, as Colin Beavan’s Fingerprints shows, the technique evolved in a circuitous way and involved fiery controversy. Prints had long been used as “signatures” in the east, and were put under some of the first microscopes in 17th-century England, but it was not until the late Victorian era that their forensic potential was spotted. Even then, the French police, for their part, long kept prints subordinate to a fileful of other bodily data – and saw them less as a way of solving crime than as the means to identify old lags, who then got stiffer sentences. Among the British, fingerprinting was first used by Sir William Herschel, an officer of the Raj, as an indisputable signature to nail down Indian natives who might otherwise fudge their identity so as to avoid paying taxes: their use for detection purposes never crossed his mind. That advance was made by Henry Faulds, a Scottish doctor working as a medical missionary in Japan, who publicised the idea in a letter to Nature in 1880. Conviction grew that no two people had identical prints. And though it then took Scotland Yard a couple of decades to develop a workable system, 1902 brought the first murder conviction in England secured principally on the basis of those loops and whorls. But then it was Herschel, not Faulds, who got the official credit for this great forensic breakthrough. The reason for this miscarriage of justice is simple, reveals Beavan: class. As the grandson of the discoverer of the planet Uranus, Sir William was a big name, and enjoyed the backing of another of science’s grandees, Charles Darwin’s cousin Francis Galton. Faulds, by contrast, was a nobody, snubbed by his superiors until he grew embittered. Now the balance is redressed, though Beavan proves himself equally guilty of a crude “heroes and villains” approach. He is also prone to journalistic cliché and linguistic lapses, while petty factual slips detract from the enjoyment of the tale he has to tell. Fingerprinting helped make forensics scientific, but one crucial aspect of detection-work long remained enigmatic: establishing the time of a crime. Everyone knew that after death the corpse undergoes a series of changes – rigor mortis, most famously, but also algor mortis (the cooling of the body) and livor mortis (the red-purple staining of the skin) – before the onset of decomposition proper. But these physical processes happen at unpredictable rates, and there were many faulty convictions upon erroneous conjectures as to how long a victim had been a carcass. Deliverance has come, as Jessica Snyder Sachs shows in her Time of Death, from a most unlikely science: entomology. Feeding and breeding habits have long been the passion of insect experts, who have meticulously documented just how long it will take for different sorts of flies to sniff out carrion, take a tasty meal of blood, and lay their eggs. In due course maggots start eating the flesh; they in turn may provide dinner for ants and other predators, and the decomposing mass then becomes inviting for successive parasites, notably beetles, until nothing is left but the bones. Without such wriggling scavengers, the earth would be awash with corpses. Only in the last few decades, however, has such entomological data systematically been applied, for courtroom purposes, to the putrefaction of human flesh. Through simulation experiments on slaughtered pigs – strewn on the ground, strung up from trees, buried in shallow graves or wrapped in bin-bags – an emerging circle of American forensic entomologists learned how to determine, even down to the hour, when precisely a certain sort of fly (blow flies, flesh flies, fruit and vinegar flies) would land on a particular corpse, when their eggs would hatch, the time of the onset of larval and pupal stages, and so forth. So, given a particular amount of maggot activity on a corpse, experts can now deduce the date and even hour of death – invaluable for checking the alibis of suspects, for identifying bodies from lists of missing persons, and also for determining the circumstances of death. The exact mix of fauna colonising a corpse further reveals whether it has been moved after death or otherwise tampered with. Additional material found in the cadaver – pollen in the nose or the contents of the stomach – help confirm nature’s insect stopwatch. Sachs is a capable science populariser, and she brings alive the somewhat creepy world of the “bug docs”, but her prose is stilted and banal (”stepping out into the March twilight, Jason Byrd drank in the silence”). Better, therefore, to get it straight from the horse’s mouth. The towering hero of forensic entomology, according to Sachs, is a larger-than-life academic, Lee Goff, a Hawaiian professor who sports a bushy beard and shaggy hair, wears a diamond stud in his ear and rides a Harley-Davidson; A Fly for the Prosecution is his first-hand account of the story of bugs on the body.What makes Goff’s book so engaging is the modest humour behind the massive expertise: comparisons with Oliver Sacks come to mind. Forensic entomology, he stresses, is still a young and quite inexact science, and the full range of factors determining decomposition rates is still being uncovered. He gets called in on a case in which the maggot feast has proceeded much faster than anticipated. Why? He notices where it was at its most intense: around the nose. Did the victim perhaps snort cocaine? Yes – eureka! Does cocaine speed up prepupal maggot activity? Try the experiment: his hunch is proved right. Unlike fingerprints, insect witnesses won’t show whodunnit, but today they are integral to science’s crime-solving toolkit. Sherlock Holmes was of the old school and remained a fingerprint sceptic; whatever would he have made of all those maggots?