This book is perhaps not the best lunchtime material: discovering the forensic importance of blowflies and their larvae (maggots) while chewing on last night’s left over Aloo Gobi and rice wouldn’t be to everyone’s taste.
However there are compensations for the inevitable moments of squeamishness. McDermid’s study of various branches of forensic investigation is fascinating.
She takes the reader from early, historical ideas and practices through to present day scientific investigative techniques, with examples given from actual cases.
“The governing principles of forensic science, as laid down by Edmond Locard at the beginning of the last century, is that ‘every contact leaves a trace’. But unless we know how to analyse, categorise and understand those traces, they’re not much use when it comes to catching criminals. As scientists have made new discoveries, so the art of detection has advanced.”
Various different disciplines come into play, through which different “traces” can be examined to determine a course of events associated with a crime, an accident, a natural death or even a war atrocity. Each chapter of Forensics highlights a different field of investigation, starting with the crime or accident scene itself.
Noted evidence can include the presence (and activity) of insects, fingerprints, blood spatter and DNA testable material. Beyond the incident scene, evidence can be examined through various means including autopsies on victims, toxicology tests (to determine the presence and effects of drugs or poisons) and DNA comparisons. Non-biological forensics are also given a couple of chapters, with digital forensics playing a part in finding evidence through computer, phone and CCTV records; while forensic psychology looks into the personalities and possible motivations of potential suspects.
While all of these disciplines have been useful in solving crimes, McDermid also refers to some instances in which forensic evidence has led to questionable results. One example given was a case in which an interpretation of fingerprint evidence led to a wrong conviction, as well as implicating police in career-ending acts of misconduct that were later shown to be unfounded.
While forensic sciences have changed the nature of crime investigation, mostly for the better, outcomes are always dependent on the experience and expertise of those reviewing and understanding what the forensic evidence means.
McDermid’s book gives an excellent, informative overview of the role of forensic sciences. My interest in the topic came about as a side-track from my recent journey into crime fiction, a diversion related to my occasional detour into true crime cases.
At the risk of using a gratuitously inappropriate metaphor, this book has helped to put some meat on the bones; giving me a better understanding of investigative practices that have been touched upon in other books I’ve read recently.