 A more principled way to assess cold-hit matches is based on the likelihood ratio. The proposal draws from the literature on the so-called island problem, studied by Eggleston (1978), Dawid (1994), and Dawid and Mortera (1996). Let the prosecutor’s hypothesis \(H_p\) be “The suspect is the source of the crime traces” and the defense hypothesis \(H_d\) be “The suspect is not the source of the crime traces”. Let \(M\) be the DNA match between the crime stain and the suspect (included in the database) and \(D\) the information that no one among the profiles in the database, except for the suspect, matches the crime stain. The likelihood ratio associated with \(M\) and \(D\) should be (Balding and Donnelly 1996; Taroni et al. 2014):