The Logic of DNA Identification

The use of DNA identification evidence during the last several decades has revolutionized forensic science. But with the increasing complexity of the systems that are now being employed, a number of foundational challenges have come to the surface: the appropriate statistic to summarize the strength of the evidence, dealing with complex samples, searching data bases, safeguarding individual privacy, and effectively communicating results to a lay audience. In this survey, after describing the current system most commonly in use, I will present a typology of these issues, focusing on the recent advent of so-called probabilistic genotyping systems, which fit high-dimensional models, sometimes using Markov chain Monte Carlo estimation, and which can be technically challenging to explain to the trier of fact.