ABSTRACT
In the above examples I assume that DNA results did not contain any errors. In real life, though, various errors can happen as the sample is being analysed. These errors can be quite common in some laboratories, extremely rare in others, but in any case when evaluating DNA evidence, the possibility of an erroneous result should be kept in mind. When the match probability is very low, the probability of a match due to error may be sufficiently high to be taken seriously and thoroughly investigated. The fact that errors in DNA analysis could happen has been recognised by Phillips LJ who during R v Doheny and Adams [1997] 1 Cr. App. R. 369 said:
(p. 373) The cogency of DNA evidence makes it particularly important that DNA testing is rigorously conducted so as to obviate the risk of error in the laboratory . . .
