The Institute of Environmental Science and Research (ESR) has changed its name to the New Zealand Institute for Public Health and Forensic Science (PHF Science) as of 1 July 2025. The website address is now www.phfscience.nz. Visitors are automatically redirected to the new address. Please check and update any links and bookmarks.

An investigation into the performance of methods for adjusting for sampling uncertainty in DNA likelihood ratio calculations

Abstract

There is a variety of methods for assessing sampling uncertainty in likelihood ratio calculations in DNA casework. Sampling uncertainty arises because all DNA statistical methods rely on a database of collected profiles. Such databases can be regarded as a sample from the population of interest. The act of taking a sample incurs sampling uncertainty. In some circumstances it may be desirable to provide some estimate of this uncertainty. We have addressed this topic in two previous publications [1], [2]. In this paper we reconsider the performance of the methods using 15 locus Identifiler™ profiles, rather than the 6 locus data used in [1]. We also examine the differences in performance observed when using a uniform prior versus a 1/k prior in the Bayesian highest posterior density (HPD) method of Curran et al. [1].

view journal