In the Beginning
Chapter 1 reviews the history of DNA analysis for individual identification in criminal cases. The principles underlying Restriction Fragment Length Polymorphism (RFLP) and Polymerase Chain Reaction (PCR) and their application in the first cases in the US and the UK in the mid-‘80s are discussed. The differences between these two DNA technologies (RFLP and PCR) are discussed and the evolution of new PCR-based genotyping methods for analyzing length and sequence polymorphisms is reviewed. The first DNA exoneration, which used the PCR-based HLA-DQ alpha test, is discussed in the context of exclusionary and inclusionary DNA results. The statistical issues involved in interpreting a match (inclusion) between the genetic profile of the evidence and the reference samples by calculating the Random Match Probability metric is discussed. Finally, the contentious history of the debate about the admissibility of DNA results in the courtroom, known as the “DNA Wars” is reviewed.