The authors propose the use of a confidence interval to report the consequent variation of likelihood ratios in interpreting mixed stain DNA evidence.
Likelihood ratios are necessary to properly interpret mixed stain DNA evidence. They can flexibly consider alternate hypotheses and can account for population substructure. The likelihood ratio should be seen as an estimate and not a fixed value, because the calculations are functions of allelic frequency estimates that were estimated from a small portion of the population. Current methods do not account for uncertainty in the likelihood ratio estimates and are therefore an incomplete picture of the strength of the evidence. In the current study, the confidence interval is calculated using the standard forensic likelihood ratio formulae and a variance estimate derived using the Taylor expansion. The formula is explained, and a computer program has been made available. Numeric work shows that the evidential strength of DNA profiles decreases as the variation among populations increases. (Published Abstract)
- Persistence of Touch DNA for Analysis
- Determining the Number of Contributors to DNA Mixtures in the Low-Template Regime Exploring the impacts of Sampling and Detection Effects
- A strategy to prioritize emerging drugs of abuse for analysis: Abuse liability testing using intracranial self-stimulation (ICSS) in rats and validation with α-pyrrolidinohexanophenone (α-PHP)