10.26091/ESRNZ.11375766.v1
Jo-Anne Bright
Jo-Anne
Bright
Kate Stevenson
Kate
Stevenson
James M. Curran
James M.
Curran
John S. Buckleton
John S.
Buckleton
The variability in likelihood ratios due to different mechanisms
Institute of Environmental Science and Research
2019
Forensic DNA
Interpretation
Likelihood ratio
Markov Chain Monte Carlo techniques
MCMC
STRmix™
Genetics
Gene Expression (incl. Microarray and other genome-wide approaches)
Forensic Biology
2019-12-18 03:29:04
Journal contribution
https://research.esr.cri.nz/articles/journal_contribution/The_variability_in_likelihood_ratios_due_to_different_mechanisms/11375766
Recently there has been a drive towards standardisation of forensic DNA interpretation methods resulting in the uptake of probabilistic interpretation software. Some of these software solutions utilise Markov chain Monte Carlo techniques (MCMC). They will not produce an identical answer after repeat interpretations of the same evidence profile because of the Monte Carlo aspect. This is a new source of variability within the forensic DNA analysis process. In this paper we explore the size of the MCMC variability within the interpretation software STRmix™ compared to other sources of variability in forensic DNA profiling including PCR, capillary electrophoresis load and injection, and the makeup of allele frequency databases. The MCMC variability within STRmix™ was shown to be the smallest source of variability in this process.