Figure 4

Expanded representations of a Bayesian network for assessing a single ‘hit’ in a database of reduced size. Bayesian network (with nodes shown in expanded form) for evaluating a correspondence between the profile of a suspect and that of a crime stain, as defined earlier in Figure 2. Fixed node states are shown in bold. The network (i) represents an initial situation in which the size of the population is N=3, and the corresponding characteristic occurs with probability γ=0.01. (ii) The state of the Bayesian network after introducing information about the non-matching individual 2 (that is, X₂). (iii) The state of the Bayesian network after adding the information that the suspect’s profile corresponds to that of the crime stain (that is, M₁). Probabilities are shown in percentages.