Book review: Silent Witnesses, by Nigel McCrery

Silent Witnesses: A History of Forensic Science
by Nigel McCrery
Random House
4 stars
Bernard Porter">

The title comes from BBC TV drama series Silent Witness; and before that from a book by American forensic chemist Paul L. Kirk, which stated: "Wherever he steps, whatever he touches, whatever he leaves, even unconsciously" - "he" being the criminal - "will serve as a silent witness against him."

Nigel McCrery is not a scientist, which means he is able to explain the subject well to other laypeople.

There can be no doubt as to the enormous contribution that forensic scientists have made to the detection of crimes over the past 150 years. Silent Witnesses concentrates on seven main areas: establishing identity (mainly fingerprinting), ballistics, discriminating between bloods, trace evidence, postmortem exams, poisons and their detection, and the great modern breakthrough of DNA.

McCrery starts with the Sumerians and finishes with the recent identification of Richard III's bones. One of the virtues of this account is that it gives proper credit to the many scientists - French, German, British, Polish, Italian, American and others - whose importance in this field is far greater than that of any real-life detectives, and more impressive than the achievements of even the most brilliant (if interestingly flawed) of our popular fictional ones.

Perhaps because science isn't as sexy as crime, McCrery pads his book out with lengthy accounts of the latter. Some are quite gruesome. Others are interesting from a sociological point of view.

Before easy divorce, for example, arsenic was a common method used by wives wishing to get rid of unwanted husbands, with all-women "schools of poisoning" set up in early modern Naples and elsewhere to pass on the mystery. That was before tests were devised to detect arsenic traces in the body. Even then these might not be conclusive evidence of murder; arsenic was widely used as a tonic and a beauty treatment too.

So forensic science alone was not always decisive. You also needed detectives.

Scientific evidence could also take time to be accepted. This could be because the details were too complicated to be understood by juries made up of ordinary people.

Now there seems to be a widespread acceptance of most of these techniques, including the most powerful one: DNA profiling. The downside is that the police would like everyone's DNA on a national database to be able to catch villains more quickly, which has implications for civil liberties.

McCrery offers no opinion on this, except to say that "it's hard to argue against its effectiveness in criminal detection".

Guardian News & Media