Forensic statistics is the application of probability models and statistical techniques to scientific evidence such as DNA evidence and the law. In contrast to everyday statistics, to not engender bias or unduly draw conclusions, forensic statisticians report likelihoods as likelihood ratios. This ratio of probabilities is then used by juries or judges to draw inferences or conclusions and decide legal matters.
Forensic statisticians evaluate evidence appropriately, you need to compare probabilities of the evidence under two different propositions.