Research paper| Volume 57, 102631, March 2022

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Using big data from probabilistic genotyping to solve crime

Published:November 20, 2021DOI:


      • Forensic Science SA implemented STRmix™ in 2012.
      • STRmix™ has deconvoluted all mixed DNA profiles at FSSA since implementation.
      • All 2019 STRmix™ analyses were interrogated to identify trends across the dataset.
      • All pairwise comparisons of deconvolutions identified common DNA donors.
      • 32 groups of linked cases were identified and could be used as police intelligence.


      Forensic Science South Australia (FSSA) has been using STRmix™ software to deconvolute all reported DNA mixtures since 2012. Almost a decade of deconvolutions had led to a substantial repository of analysed profile data that can be interrogated to observe trends in case type, location or occurrence. In addition, deconvolutions can be compared in order to identify common DNA donors and reveal new intelligence information in cases where DNA profiling has previously provided no investigative information. As a proof of concept all samples deconvoluted as part of criminal casework (suspect or no-suspect) were interrogated and compared to each other using the mixture-to-mixture comparison feature in STRmix™. Within the Adelaide region there were 32 groups of cases that had evidence samples linked by a common DNA donor with LR > 1 million which was in addition to direct links and mixture searching links identified previously. These groups of cases can then be interrogated to reveal additional information to inform Police intelligence gathering. Our paper reports on the findings of this proof-of-concept study.


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        • Martin P.D.
        • Schmitter H.
        • Schneider P.M.
        A brief history of the formation of DNA databases in forensic science within Europe.
        Forensic Sci. Int. 2001; 119: 225-231
      1. National DNA Database statistics, Q41 2020 to 2021. <〈〉>, (Accessed 14 May 2021.).

        • Amankwaa A.O.
        Trends in forensic DNA database: transnational exchange of DNA data.
        Forensic Sci. Res. 2020; 5: 8-14
        • Taylor D.
        • Bright J.-A.
        • Buckleton J.
        The interpretation of single source and mixed DNA profiles.
        Forensic Sci. Int. Genet. 2013; 7: 516-528
        • Coble M.
        • Bright J.-A.
        Probabilistic genotyping software: an overview.
        Forensic Sci. Int. Genet. 2019; 38: 219-224
        • Bright J.-A.
        • Taylor D.
        • Curran J.
        • Buckleton J.
        Searching mixed DNA profiles directly against profile databases.
        Forensic Sci. Int. Genet. 2014; 9: 102-110
        • Slooten K.
        A top-down approach to DNA mixtures.
        Forensic Sci. Int. Genet. 2020; 46
        • Taylor D.
        • Bright J.-A.
        • Scandrett L.
        • Abarno D.
        • Lee S.-I.
        • Wivell R.
        • Kelly H.
        • Buckleton J.
        Validation of a top-down DNA profile analysis for database searching using a fully continuous probabilistic genotyping model.
        Forensic Sci. Int. Genet. Rev. 2021;
        • Collins T.E.
        • Abarno D.V.
        Assessment of changes to DNA database interrogation at Forensic Science SA.
        Aust. J. Forensic Sci. 2019; 51: S68-S71
        • Taylor D.
        • Kruijver M.
        Combining evidence across multiple mixed DNA profiles for improved resolution of a donor when a common contributor can be assumed.
        Forensic Sci. Int. Genet. 2020; 49102375
        • Kruijver M.
        • Taylor D.
        • Bright J.-A.
        Evaluating DNA evidence possibly involving multiple (mixed) samples, common donors and related contributors.
        Forensic Sci. Int. Genet. Rev. 2021;
        • Slooten K.
        Identifying common donors in DNA mixtures, with applications to database searches.
        Forensic Sci. Int. Genet. 2017; 26: 40-47
        • Taylor D.
        • Rowe E.
        • Kruijver M.
        • Abarno D.
        • Bright J.-A.
        • Buckleton J.
        Inter-sample contamination detection using mixture deconvolution comparison.
        Forensic Sci. Int. Genet. 2019; 40: 160-167
        • Jeuniaux P.P.J.M.H.
        • Duboccage L.
        • Renard B.
        • Van Renterghem P.
        • Vanvooren V.
        Establishing networks in a forensic DNA database to gain operational and strategic intelligence.
        Secur. J. 2016; 29: 584-602
        • R Core Team
        R: A language and environment for statistical computing.
        R Foundation for Statistical Computing, Vienna, Austria2013
      2. I. Fellows, OpenStreetMap: Access to Open Street Map Raster Images V0.3.4, (〈〉) (2019).

        • Dubrich J.
        • Abarno D.
        Maximizing intelligence obtained from higher-order DNA mixtures from volume crime samples.
        Aust. J. Forensic Sci. 2019; 51: S259-S262
        • Rossmo D.K.
        Geographic Profiling.
        first ed. CRC Press Taylor & Francis Group, 2000
        • Bleka Ø.
        • Prieto L.
        • Gill P.
        CaseSolver: an investigative open source expert system based on EuroForMix.
        Forensic Sci. Int. Genet. 2019; 41: 83-92
        • Buckleton J.S.
        • Pugh S.N.
        • Bright J.-A.
        • Taylor D.A.
        • Curran J.M.
        • Kruijver M.
        • Gill P.
        • Budowle B.
        • Cheng K.
        Are low LRs reliable?.
        Forensic Sci. Int. Genet. 2020; 49
        • Buckleton J.
        • Triggs C.
        Relatedness and DNA: are we taking it seriously enough?.
        Forensic Sci. Int. 2005; 152: 115-119
        • Zoete Jd
        • Sjerps M.
        • Meester R.
        Evaluating evidence in linked crimes with multiple offenders.
        Forensic Sci. Int. Genet. 2017;