Sir Alec Jeffreys developed DNA profiling in the genetics department at the University of Leicester during the mid-1980s, revolutionising forensic science and stimulating a sizeable popular literature on the subject. As DNA databases have grown - particularly in the UK, which has enthusiastically genotyped 4.5 million of its citizens - concern has been voiced in many quarters about whether the privacy of the individual may be compromised. Genetic Justice tackles these issues head on from the viewpoint of civil liberties, and comes up with lively prose and a nicely balanced argument that is engaging and informative.
The book starts with a description of a series of crimes, mostly in Germany and including six murders, stretching over a period of 15 years. Through the DNA collected at the scenes, police believed that the same woman had been responsible for each felony. Some R12 million was spent trying to track her down until it was realised that the DNA came from an innocent woman who worked at the factory that made the swabs used for collecting DNA at the crime scenes.
Given this introduction, I thought the rest of the book would be in much the same vein, with the authors bashing DNA evidence at every opportunity. Not a bit of it; and to their credit, they provide a compelling and largely objective account of the field, and the implications that it has for every single one of us.
Sheldon Krimsky and Tania Simoncelli begin by explaining how DNA tests work and how the various databases have been set up and connected to each other. When there is no single suspect, they argue that DNA dragnets - whereby hundreds or thousands of potential suspects, usually living near the crime scene, are asked to provide their DNA in order to be excluded from the investigation - represent a waste of resources and rarely find the culprit. More useful are familial DNA searches, where partial DNA matches to a crime scene are found in the relatives of the perpetrators (the relatives' DNA having found its way on to a database, usually because of a misdemeanour).
The authors then compare the idiosyncrasies of DNA forensics in five countries. Every chapter is laced with real examples: both successes, where prosecutions and exonerations have resulted from DNA evidence, often from "cold case files"; and failures, in which poor laboratory practice led to unsafe convictions.
However, the main theme here is the issue of privacy. Suspects have unwittingly been the subject of elaborate police ruses in order to obtain their DNA without their permission, from saliva on cigarettes, for example. Defence lawyers have argued that such evidence should be inadmissible. It is a thorny subject, and some countries, notably the UK, are acknowledging that the DNA we shed in saliva or hair should not be analysed without our permission.
Another controversial issue is whether there should be a universal DNA database, as proposed by former prime minister Tony Blair. Existing databases are predominantly composed of the DNA of suspects, convicted or not, and are biased towards specific racial groups. The authors argue that the immense expense and the logistics of such an undertaking far exceed any benefits, and they stand firmly against the perceived inevitability of such a programme.
The authors end with a final flourish on balancing privacy and security in a liberal society. Although I cannot do full justice to a book of more than 400 pages in a few paragraphs, it is by far the best of the genre that I have read, and I recommend it to anyone interested in this topical and controversial subject.
Genetic Justice: DNA Data Banks, Criminal Investigations, and Civil Liberties
By Sheldon Krimsky and Tania Simoncelli. Columbia University Press. 448pp, £19.95. ISBN 9780231145206. Published 20 January 2011