Logical evaluation of evidence when a person is suspected of committing two separate offences.
We consider the problem of drawing inferences within a legal framework when a person is a suspect for two separate offences. Although we are primarily concerned with scientific evidence the issue inevitably arises as to how that evidence interacts with other, non-scientific evidence. We show that, in this particular context, the evidence can be conveniently classified into three categories that concern, respectively: the first crime only; the second crime only; and evidence that relates to similarities between the two crimes. Two case examples are considered and we consider DNA, fibres and eyewitness evidence. These are viewed from the perspective of a prosecutor who has to decide whether or not to charge a suspect with one or both crimes. Graphical sensivity analyses are presented which have features that are not intuitively obvious.
Evett
I W
IW
Forensic Science Service, London, UK. ianevett@aol.com
Jackson
G
G
Lindley
D V
DV
Meuwly
D
D
D003416:Criminal Law; D016172:DNA Fingerprinting; D003627:Data Interpretation, Statistical; D006801:Humans; D016013:Likelihood Functions; D011336:Probability; D013784:Textiles