title: Probabilistically determining the cellular source of DNA derived from differential extractions in sexual assault scenarios.
abstract: Sexual assault cases are the type of case that often produces questions about the cellular source of DNA. In these cases multiple findings of microscopy, DNA profiling and presumptive testing need to be considered when addressing source level propositions. In this work, I consider a line of questioning that has been raised a number of times in the recent past, where in court it was disputed that low levels of sperm seen on a microscope slide were the cellular source of the male DNA profile component generated from the sperm fraction of a differential DNA extraction. I demonstrate how the cell scoring results and DNA profiling results can be considered together, in helping address this source level question through the use of Bayesian Networks.
authors.affiliation: Forensic Science South Australia, 21 Divett Place, Adelaide, SA 5000, Australia; School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia. Electronic address: Duncan.Taylor@sa.gov.au.
authors.forename: Duncan
authors.initials: D
authors.lastname: Taylor
mesh_terms: D004247:DNA / Q000032:analysis*; D016172:DNA Fingerprinting / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D012742:Sex Offenses; D013094:Spermatozoa / Q000737:chemistry* / Q000166:cytology
chemical_list: D004247:DNA
keywords: Bayesian networks; Differential extraction; Likelihood ratio; Sexual assault; Source level propositions; Sperm scoring