Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

In comparing a particular DNA profile with that from an unknown (but distinct) individual, matches at different loci between the profiles will not be independent, even in a randomly mating population, because of the presence in the population of relatives of the individuals. The paper contains a theoretical analysis of the extent of this effect on the match probability, for profiling techniques which separately probe different loci. Naive calculation using the product rule could substantially understate the match probability. Past a certain point, the testing of additional loci provides no more information than would be available in discriminating between sibs. The correlation effect described here would be unimportant in criminal casework if close relatives of the suspect, and in particular full-sibs, were excluded as possible culprits. In the absence of such exclusions the current practice of effectively ignoring such relatives in presenting match probabilities could be extremely prejudicial to a suspect, even in cases in which there is no direct evidence to incriminate his/her relatives.

Original publication




Journal article


Heredity (Edinb)

Publication Date



75 ( Pt 1)


26 - 34


Alleles, DNA Fingerprinting, DNA Probes, Female, Genotype, Humans, Interpersonal Relations, Linkage Disequilibrium, Male, Minisatellite Repeats, Models, Genetic, Probability