A fully continuous system of DNA profile evidence evaluation that can utilise STR profile data produced under different conditions within a single analysis. (November 2017)

• Record Type: Journal Article
• Authors: Taylor, Duncan; Bright, Jo-Anne; Kelly, Hannah; Lin, Meng-Han; Buckleton, John
• Is Part Of: Forensic science international. Volume 31(2017)
• Page Start: 149
• Page End: 154
• Publication Date: 2017-11
• Subjects: Multiple DNA profiling kits -- Continuous DNA interpretation -- STRmix -- Modelling -- DNA mixtures; Forensic genetics -- Periodicals; Génétique légale -- Périodiques; Forensic genetics; Electronic journals; Periodicals; 614.1
• DOI: 10.1016/j.fsigen.2017.09.002
• Languages: English
• ISSNs: 1872-4973

Abstract

Highlights: We explain several casework situations that can arise which require evaluation of DNA profile replicates that span a technology change. When a likelihood ratio is required for these types of evaluations, the classic approach has been to pick one of the replicates. We present the maths for the interpretation system STRmix™ to allow the combination of replicates produced under different conditions. We demonstrate the performance of the proposed model on situations which may be encountered in the laboratory. Abstract: The introduction of probabilistic DNA interpretation systems has made it possible to evaluate many profiles that previously (under a manual interpretation system) were not. These probabilistic systems have been around for a number of years and it is becoming more common that their use within a laboratory has spanned at least one technology change. This may be a change in laboratory hardware, the DNA profiling kit used, or the manner in which the profile is generated. Up until this point, when replicates DNA profiles are generated, that span a technological change, the ability to utilise all the information in all replicates has been limited or non-existent. In this work we explain and derive the models required to evaluate (what we term) multi-kit analysis problems. We demonstrate the use of the multi-kit feature on a number of scenarios where such an analysis would be desired within a laboratory. Allowing the combination of profiling data that spans a technological change will further increase the amount of DNA profile information produced in a laboratory that can be evaluated.