Highlights
- •A Bayesian network is described to help address questions regarding the cellular source of DNA from differential extractions.
- •Sperm and epithelial scoring from microscopy and DNA profiling results are considered within the Bayesian Network.
- •Sensitivity analysis shows that in many instances it is possible to provide strong levels of support to an individual having donating sperm (or not) to a trace.
- •Further experimental work is suggested that will assist in assigning probabilities to nodes within the network, or to refine the network structure.
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.
Keywords
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Article info
Publication history
Published online: June 18, 2016
Accepted:
June 17,
2016
Received in revised form:
May 31,
2016
Received:
March 6,
2016
Identification
Copyright
© 2016 Elsevier Ireland Ltd. All rights reserved.
