Figure 5

Bayesian network for a search of a database of size n > 2. Structure of a Bayesian network for evaluating a correspondence (M₁) between the profile of a crime stain and that of a sample from a suspect when the suspect is on a database along with n−1 other individuals. The size of the population of potential offenders is N where n (with n≤N) of them are on a database. The node H has three states: ‘the suspect is the source of the crime stain’ (H₁), ‘one of the n−1 other individuals in the database is the source of the crime stain’ ($H_{2\text{\_}n}$), and ‘the source of the crime stain is among the N−n individuals outside the database’ ($H_{n+1\text{\_}N}$). The corresponding genetic feature occurs in the population with rate γ. The node X₂&…&X _n is binary and represents the proposition according to which the profiles of the n−1 individuals in the database, other than the suspect, do not correspond to the crime stain.