DNA profiling (6 - and last!)

Most of what I've had to say about DNA profiling over this series of posts has been negative, which may have led you to think that I am opposed to it. But nothing could be further from the truth - DNA profiling is a very useful evidential tool, provided it is used responsibly. And it's those last five words that are important. It is not the magic wand which the public are encouraged to believe it is, and which many police and prosecutors have convinced themselves that it is. It is far from unusual to (1) get a false match and (2) recover traces of a person's DNA from somewhere they have never been. And of course like any other physical evidence, DNA can be "planted". And then, for jurors, the question they should be asking themselves is not how unlikely is it that this DNA profile would be obtained from an innocent person, but how likely is it that a person who has this DNA profile is innocent? If we take all these caveats on board, then DNA profiling is an important addition to the evidentiary armory of the forces of law and order. But it's important that we don't get carried away and try to over-egg the pudding.