The impact of parameter variation in the quantification of forensic genetic evidence

Abstract Technological advancements have allowed the detection of increasingly complex forensic genetics samples, as minimum amounts of DNA can now be detected in crime scenes or other settings of interest. The weight of the evidence depends on several parameters regarding the population and sample-...

Full description

Saved in:
Bibliographic Details
Main Authors: Camila Costa, Carolina Figueiredo, Sandra Costa, Paulo Miguel Ferreira, António Amorim, Lourdes Prieto, Nádia Pinto
Format: Article
Language:English
Published: Nature Portfolio 2025-01-01
Series:Scientific Reports
Subjects:
Online Access:https://doi.org/10.1038/s41598-024-83841-2
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832585853765943296
author Camila Costa
Carolina Figueiredo
Sandra Costa
Paulo Miguel Ferreira
António Amorim
Lourdes Prieto
Nádia Pinto
author_facet Camila Costa
Carolina Figueiredo
Sandra Costa
Paulo Miguel Ferreira
António Amorim
Lourdes Prieto
Nádia Pinto
author_sort Camila Costa
collection DOAJ
description Abstract Technological advancements have allowed the detection of increasingly complex forensic genetics samples, as minimum amounts of DNA can now be detected in crime scenes or other settings of interest. The weight of the evidence depends on several parameters regarding the population and sample-related analytical factors, the latter in a greater number when the DNA amount is considered. This led to the development of probabilistic genotyping software (PGS), able to deal with the associated complexities. This study aims to evaluate the impact on the evidence’s weighing, when different analytical threshold values are used, and when different models and/or estimates for analytical artifacts, such as stutters or drop-in parameters, are considered. To reach this goal, three PGS, based on different statistical models, were used to analyze real casework pairs of samples composed of a mixture with either two or three estimated contributors, and a single-source sample associated. The obtained results show that the estimation of these parameters must not be overlooked, as they may considerably impact the outcome. This underlines the importance of proper parametrization in the analysis of forensic genetics identification problems when using complex samples, and the understanding by practitioners of how probabilistic genotyping informatics tools work to use them accurately.
format Article
id doaj-art-81bf56bf7a7f429abc523ae38800d748
institution Kabale University
issn 2045-2322
language English
publishDate 2025-01-01
publisher Nature Portfolio
record_format Article
series Scientific Reports
spelling doaj-art-81bf56bf7a7f429abc523ae38800d7482025-01-26T12:26:43ZengNature PortfolioScientific Reports2045-23222025-01-0115111210.1038/s41598-024-83841-2The impact of parameter variation in the quantification of forensic genetic evidenceCamila Costa0Carolina Figueiredo1Sandra Costa2Paulo Miguel Ferreira3António Amorim4Lourdes Prieto5Nádia Pinto6Departamento de Biologia, Faculdade de Ciências, Universidade do PortoDepartamento de Biologia, Faculdade de Ciências, Universidade do PortoBiologia, Laboratório de Polícia Científica da Polícia Judiciaria (LPC-PJ)Biologia, Laboratório de Polícia Científica da Polícia Judiciaria (LPC-PJ)Departamento de Biologia, Faculdade de Ciências, Universidade do PortoGrupo de Medicina Xenómica, Instituto de Ciencias Forenses, Universidad de Santiago de Compostelai3S - Instituto de Investigação e Inovação em Saúde, Universidade do PortoAbstract Technological advancements have allowed the detection of increasingly complex forensic genetics samples, as minimum amounts of DNA can now be detected in crime scenes or other settings of interest. The weight of the evidence depends on several parameters regarding the population and sample-related analytical factors, the latter in a greater number when the DNA amount is considered. This led to the development of probabilistic genotyping software (PGS), able to deal with the associated complexities. This study aims to evaluate the impact on the evidence’s weighing, when different analytical threshold values are used, and when different models and/or estimates for analytical artifacts, such as stutters or drop-in parameters, are considered. To reach this goal, three PGS, based on different statistical models, were used to analyze real casework pairs of samples composed of a mixture with either two or three estimated contributors, and a single-source sample associated. The obtained results show that the estimation of these parameters must not be overlooked, as they may considerably impact the outcome. This underlines the importance of proper parametrization in the analysis of forensic genetics identification problems when using complex samples, and the understanding by practitioners of how probabilistic genotyping informatics tools work to use them accurately.https://doi.org/10.1038/s41598-024-83841-2Forensic DNAMixture samplesLikelihood ratioDrop-inAnalytical thresholdStutters
spellingShingle Camila Costa
Carolina Figueiredo
Sandra Costa
Paulo Miguel Ferreira
António Amorim
Lourdes Prieto
Nádia Pinto
The impact of parameter variation in the quantification of forensic genetic evidence
Scientific Reports
Forensic DNA
Mixture samples
Likelihood ratio
Drop-in
Analytical threshold
Stutters
title The impact of parameter variation in the quantification of forensic genetic evidence
title_full The impact of parameter variation in the quantification of forensic genetic evidence
title_fullStr The impact of parameter variation in the quantification of forensic genetic evidence
title_full_unstemmed The impact of parameter variation in the quantification of forensic genetic evidence
title_short The impact of parameter variation in the quantification of forensic genetic evidence
title_sort impact of parameter variation in the quantification of forensic genetic evidence
topic Forensic DNA
Mixture samples
Likelihood ratio
Drop-in
Analytical threshold
Stutters
url https://doi.org/10.1038/s41598-024-83841-2
work_keys_str_mv AT camilacosta theimpactofparametervariationinthequantificationofforensicgeneticevidence
AT carolinafigueiredo theimpactofparametervariationinthequantificationofforensicgeneticevidence
AT sandracosta theimpactofparametervariationinthequantificationofforensicgeneticevidence
AT paulomiguelferreira theimpactofparametervariationinthequantificationofforensicgeneticevidence
AT antonioamorim theimpactofparametervariationinthequantificationofforensicgeneticevidence
AT lourdesprieto theimpactofparametervariationinthequantificationofforensicgeneticevidence
AT nadiapinto theimpactofparametervariationinthequantificationofforensicgeneticevidence
AT camilacosta impactofparametervariationinthequantificationofforensicgeneticevidence
AT carolinafigueiredo impactofparametervariationinthequantificationofforensicgeneticevidence
AT sandracosta impactofparametervariationinthequantificationofforensicgeneticevidence
AT paulomiguelferreira impactofparametervariationinthequantificationofforensicgeneticevidence
AT antonioamorim impactofparametervariationinthequantificationofforensicgeneticevidence
AT lourdesprieto impactofparametervariationinthequantificationofforensicgeneticevidence
AT nadiapinto impactofparametervariationinthequantificationofforensicgeneticevidence