Modeling the forensic two-trace problem with Bayesian networks
- 316 Downloads
The forensic two-trace problem is a perplexing inference problem introduced by Evett (J Forensic Sci Soc 27:375–381, 1987). Different possible ways of wording the competing pair of propositions (i.e., one proposition advanced by the prosecution and one proposition advanced by the defence) led to different quantifications of the value of the evidence (Meester and Sjerps in Biometrics 59:727–732, 2003). Here, we re-examine this scenario with the aim of clarifying the interrelationships that exist between the different solutions, and in this way, produce a global vision of the problem. We propose to investigate the different expressions for evaluating the value of the evidence by using a graphical approach, i.e. Bayesian networks, to model the rationale behind each of the proposed solutions and the assumptions made on the unknown parameters in this problem.
KeywordsEvaluation of evidence Value of the evidence Graphical probability models Bayesian networks Two-trace problem
This research was supported by the Swiss National Science Foundation grant n° 100014-122601/1.
- Dawid AP (2004) Which likelihood ratio? Comment on ‘Why the effect of prior odds should accompany the likelihood ratio when reporting DNA evidence’ by R. Meester and M. Sjerps. Law Prob Risk 3:65–71Google Scholar
- Edwards W (1991) Influence diagrams, Bayesian imperialism, and the Collins case: an appeal to reason. Cardozo Law Rev 13:1025–1079Google Scholar
- Fenton NE, Neil M (2011) Avoiding probabilistic reasoning fallacies in legal practice using Bayesian networks. Aust J Leg Philos 36:114–151Google Scholar
- Fenton NE, Neil M, Lagnado D (2011) Modelling mutually exclusive causes in Bayesian networks. Working paper. http://www.eecs.qmul.ac.uk/~norman/papers/mutual_IEEE_format_version.pdf. Accessed 8 Oct 2012
- Garbolino P (2001) Explaining relevance. Cardozo Law Rev 22:1503–1521Google Scholar
- Kadane JB, Schum DA (1996) A probabilistic analysis of the Sacco and Vanzetti evidence. Wiley, New YorkGoogle Scholar
- Lindley DV (2000) The philosophy of statistics. Statistician 49:293–337Google Scholar
- Meester R, Sjerps M (2004b) Response to Dawid, Balding, Triggs and Buckleton (concerning: why the effect of prior odds should accompany the likelihood ratio when reporting DNA evidence. Law, Prob. and Risk 3:51–62). Law Prob Risk 3:83–86Google Scholar
- Robertson B, Vignaux GA (1995) Interpreting evidence. Wiley, ChichesterGoogle Scholar
- Schum DA (1994) The evidential foundations of probabilistic reasoning. Wiley, New YorkGoogle Scholar
- Thompson WC, Taroni F, Aitken CGG (2003) How the probability of a false positive affects the value of DNA evidence. J Forensic Sci 48:47–54Google Scholar