An alternative application of the consensus method to DNA typing interpretation for Low Template-DNA mixtures

• Published in: Forensic science international. Genetics supplement series 2015-12, Vol.5, p.e422-e424
• Main Authors: Garofano, Paolo, Caneparo, Denise, D’Amico, Giuseppina, Vincenti, Marco, Alladio, Eugenio
• Format: Article
• Language: English
• Subjects: DNA•VIEW; Fully continuous model; Lab Retriever; LRmix Studio; LT DNA; Mixture interpretation; Semi-continuous model
• ISSN: 1875-1768; 1875-175X
• DOI: 10.1016/j.fsigss.2015.09.168

Aim of this study is to define a rigorous approach to Low Template-DNA mixture interpretation; our laboratory adopted two different models, i.e. the semi-continuous method (with the use of LRmix Studio and Lab Retriever software) and the fully continuous method (with the use of DNA•VIEW™ software). When approaching caseworks where complex DNA profiles are involved, evidence evaluation may heavily affect the outcome of a Trial so extreme caution is needed in order to achieve correct results’ interpretation. As consequence of this, a conservative “statistic consensus method” was developed and validated on simulated LT-DNA mixture and then applied in real casework. In particular, our statistic consensus approach consists in comparing likelihood ratio values provided by different software and, only if results turn out to be convergent, the most conservative likelihood ratio value is finally reported. On the contrary, if likelihood ratio results are not convergent, DNA interpretation is considered inconclusive.