Back to Search
Start Over
Four model variants within a continuous forensic DNA mixture interpretation framework: Effects on evidential inference and reporting
- Source :
- PLoS ONE, PLoS ONE, Vol 13, Iss 11, p e0207599 (2018)
- Publication Year :
- 2018
-
Abstract
- Continuous mixture interpretation methods that employ probabilistic genotyping to compute the Likelihood Ratio (LR) utilize more information than threshold-based systems. The continuous interpretation schemes described in the literature, however, do not all use the same underlying probabilistic model and standards outlining which probabilistic models may or may not be implemented into casework do not exist; thus, it is the individual forensic laboratory or expert that decides which model and corresponding software program to implement. For countries, such as the United States, with an adversarial legal system, one can envision a scenario where two probabilistic models are used to present the weight of evidence, and two LRs are presented by two experts. Conversely, if no independent review of the evidence is requested, one expert using one model may present one LR as there is no standard or guideline requiring the uncertainty in the LR estimate be presented. The choice of model determines the underlying probability calculation, and changes to it can result in non-negligible differences in the reported LR or corresponding verbal categorization presented to the trier-of-fact. In this paper, we study the impact of model differences on the LR and on the corresponding verbal expression computed using four variants of a continuous mixture interpretation method. The four models were tested five times each on 101, 1-, 2- and 3-person experimental samples with known contributors. For each sample, LRs were computed using the known contributor as the person of interest. In all four models, intra-model variability increased with an increase in the number of contributors and with a decrease in the contributor's template mass. Inter-model variability in the associated verbal expression of the LR was observed in 32 of the 195 LRs used for comparison. Moreover, in 11 of these profiles there was a change from LR > 1 to LR < 1. These results indicate that modifications to existing continuous models do have the potential to significantly impact the final statistic, justifying the continuation of broad-based, large-scale, independent studies to quantify the limits of reliability and variability of existing forensically relevant systems.
- Subjects :
- 0301 basic medicine
Forensic Genetics
Heredity
Computer science
Normal Distribution
lcsh:Medicine
Inference
Social Sciences
Artificial Gene Amplification and Extension
computer.software_genre
Polymerase Chain Reaction
0302 clinical medicine
Medicine and Health Sciences
Psychology
lcsh:Science
Reliability (statistics)
Statistic
Verbal Communication
Likelihood Functions
Multidisciplinary
Applied Mathematics
Simulation and Modeling
Clinical Laboratory Sciences
Genetic Mapping
Categorization
Physical Sciences
Algorithms
Research Article
Genotyping
Sample (statistics)
Variant Genotypes
Machine learning
Research and Analysis Methods
Normal distribution
03 medical and health sciences
Diagnostic Medicine
Genetics
Humans
030216 legal & forensic medicine
Molecular Biology Techniques
Molecular Biology
Forensics
Behavior
Models, Statistical
business.industry
Verbal Behavior
lcsh:R
Probabilistic logic
Biology and Life Sciences
Statistical model
Probability Theory
Probability Distribution
DNA Fingerprinting
United States
030104 developmental biology
Genetic Loci
lcsh:Q
Law and Legal Sciences
Artificial intelligence
business
computer
Software
Mathematics
Subjects
Details
- ISSN :
- 19326203
- Volume :
- 13
- Issue :
- 11
- Database :
- OpenAIRE
- Journal :
- PloS one
- Accession number :
- edsair.doi.dedup.....e511becaf3fc1da6f56eecec8b700f30