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Determining the optimal forensic DNA analysis procedure following investigation of sample quality

Hedell, Ronny; Hedman, Johannes LU and Mostad, Petter (2018) In International Journal of Legal Medicine 132(4). p.955-966
Abstract

Crime scene traces of various types are routinely sent to forensic laboratories for analysis, generally with the aim of addressing questions about the source of the trace. The laboratory may choose to analyse the samples in different ways depending on the type and quality of the sample, the importance of the case and the cost and performance of the available analysis methods. Theoretically well-founded guidelines for the choice of analysis method are, however, lacking in most situations. In this paper, it is shown how such guidelines can be created using Bayesian decision theory. The theory is applied to forensic DNA analysis, showing how the information from the initial qPCR analysis can be utilized. It is assumed the alternatives for... (More)

Crime scene traces of various types are routinely sent to forensic laboratories for analysis, generally with the aim of addressing questions about the source of the trace. The laboratory may choose to analyse the samples in different ways depending on the type and quality of the sample, the importance of the case and the cost and performance of the available analysis methods. Theoretically well-founded guidelines for the choice of analysis method are, however, lacking in most situations. In this paper, it is shown how such guidelines can be created using Bayesian decision theory. The theory is applied to forensic DNA analysis, showing how the information from the initial qPCR analysis can be utilized. It is assumed the alternatives for analysis are using a standard short tandem repeat (STR) DNA analysis assay, using the standard assay and a complementary assay, or the analysis may be cancelled following quantification. The decision is based on information about the DNA amount and level of DNA degradation of the forensic sample, as well as case circumstances and the cost for analysis. Semi-continuous electropherogram models are used for simulation of DNA profiles and for computation of likelihood ratios. It is shown how tables and graphs, prepared beforehand, can be used to quickly find the optimal decision in forensic casework.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Allele dropout, Bayesian decision theory, DNA degradation, DNA quantification, PCR
in
International Journal of Legal Medicine
volume
132
issue
4
pages
955 - 966
publisher
Springer
external identifiers
  • scopus:85024504212
ISSN
0937-9827
DOI
10.1007/s00414-017-1635-1
language
English
LU publication?
yes
id
7cb4076f-6176-4a0d-8711-a96fc235dc4f
date added to LUP
2018-01-25 12:31:24
date last changed
2019-02-20 11:05:43
@article{7cb4076f-6176-4a0d-8711-a96fc235dc4f,
  abstract     = {<p>Crime scene traces of various types are routinely sent to forensic laboratories for analysis, generally with the aim of addressing questions about the source of the trace. The laboratory may choose to analyse the samples in different ways depending on the type and quality of the sample, the importance of the case and the cost and performance of the available analysis methods. Theoretically well-founded guidelines for the choice of analysis method are, however, lacking in most situations. In this paper, it is shown how such guidelines can be created using Bayesian decision theory. The theory is applied to forensic DNA analysis, showing how the information from the initial qPCR analysis can be utilized. It is assumed the alternatives for analysis are using a standard short tandem repeat (STR) DNA analysis assay, using the standard assay and a complementary assay, or the analysis may be cancelled following quantification. The decision is based on information about the DNA amount and level of DNA degradation of the forensic sample, as well as case circumstances and the cost for analysis. Semi-continuous electropherogram models are used for simulation of DNA profiles and for computation of likelihood ratios. It is shown how tables and graphs, prepared beforehand, can be used to quickly find the optimal decision in forensic casework.</p>},
  author       = {Hedell, Ronny and Hedman, Johannes and Mostad, Petter},
  issn         = {0937-9827},
  keyword      = {Allele dropout,Bayesian decision theory,DNA degradation,DNA quantification,PCR},
  language     = {eng},
  number       = {4},
  pages        = {955--966},
  publisher    = {Springer},
  series       = {International Journal of Legal Medicine},
  title        = {Determining the optimal forensic DNA analysis procedure following investigation of sample quality},
  url          = {http://dx.doi.org/10.1007/s00414-017-1635-1},
  volume       = {132},
  year         = {2018},
}