Response to: Use of prior odds for missing persons identifications - authors' reply

We are concerned that statisticians, such as Biedermann et al. [1], advocate the position that data may not be needed to support assumptions 'as long as probability is properly considered as an expression of personal belief'. At a time when the National Academy of Sciences [2] has urged the need for the forensic science community to provide reliable results based on 'objective' data, these authors' position cannot be reconciled. The Report noted (on its page 8), 'The simple reality is that the interpretation of forensic evidence is not always based on scientific studies to determine its validity ... A body of research is required to establish the limits and measures of performance and to address the impact of sources of variability and potential bias. Such research is sorely needed, but it seems to be lacking in most of the forensic disciplines that rely on subjective assessments of matching characteristics. These disciplines need to develop rigorous protocols to guide these subjective interpretations and pursue equally rigorous research and evaluation programs'. It is this approach that distinguishes science from other epistemologies. Then the Report called for research in its Recommendation 3 (page 23), 'Research is needed to address issues of accuracy, reliability, and validity in the forensic science disciplines ... [and in section c of Recommendation 3] the development of quantifiable measures of uncertainty in the conclusions of forensic analyses'.Foremost, none should abide the inclusion of overstated evidence in reports or legal proceedings as it can impinge on the presumption of innocence. The tenet of this presumption should be held dearly by all, and we as scientists should strive to reduce practices that cannot be supported. Biedermann et al. [1] appear to argue that, because there is 'subjectivity in science', one does not necessarily have to be held to a standard of justifying assumptions. It is well accepted that there is subjectivity in science. Inde