Titre
Value of DNA mixture-to-mixture comparisons within an operational context.
Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Périodique
Auteur(s)
Basset, P.
Auteure/Auteur
Toulemont, L.
Auteure/Auteur
Hicks, T.
Auteure/Auteur
Castella, V.
Auteure/Auteur
Liens vers les personnes
ISSN
1878-0326
Statut éditorial
Publié
Date de publication
2024-11
Volume
73
Première page
103110
Peer-reviewed
Oui
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Publication Status: ppublish
Résumé
Since 1995, national forensic DNA databases have used a maximum number of contributors, and a minimum number of loci to reduce the risk of providing false leads. DNA profiles of biological traces that do not meet these criteria cannot be loaded into these databases. In 2023, about 10 % of more than 15,000 trace DNA profiles analyzed in western Switzerland were not compared at the national level, even though they were considered to be interpretable, mainly because they contained the DNA from more than two persons. In this situation, police services can request local comparisons with DNA profiles of known persons and/or with other traces, but this occurs in only a small proportion of cases, so that DNA mixtures are rarely used to help detect potential series. The development of probabilistic genotyping software and its associated tools have made possible the efficient performance of this type of comparison, which is based on likelihood ratios (LR) rather than on the number of shared alleles. To highlight potential common contributors for investigation and intelligence purposes, the present study used the mixture-to-mixture tool of the software STRmix v2.7 to compare 235 DNA profiles that cannot be searched the Swiss DNA database. These DNA profiles originated from traces collected by six different police services in 2021 and 2022. Traces were selected by the police based on information that indicated that they were from potential series. Associations between profiles were compared with expected investigative associations to define the value of this approach. Among the 27,495 pairwise comparisons of DNA profiles, 88 pairs (0.3 %) showed at least one potential common contributor when using a LR threshold of 1000. Of these 88 pairs, 60 (68.2 %) were qualified by the police services as "expected" (60/88), 22 (25.0 %) as "possible", and six (6.8 %) as "unexpected". Although it is important to consider the limits of this approach (e.g., adventitious or missed associations, cost/benefit evaluation, integration of DNA mixture comparison in the process), these findings indicate that non CODIS loadable DNA mixtures could provide police agencies with information concerning potential series at both the local and national level.
PID Serval
serval:BIB_B8D6F7135518
PMID
Open Access
Oui
Date de création
2024-08-09T13:25:36.930Z
Date de création dans IRIS
2025-05-21T00:45:52Z
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Nom
39098056.pdf
Version du manuscrit
published
Licence
https://creativecommons.org/licenses/by/4.0
Taille
1.5 MB
Format
Adobe PDF
PID Serval
serval:BIB_B8D6F7135518.P001
URN
urn:nbn:ch:serval-BIB_B8D6F71355183
Somme de contrôle
(MD5):4df5fe8b1d1395b509b532b9f5a59a1e