Earmarks as evidence: a critical review.

The use of earmarks as evidence in criminal trials appears to be expanding, but there is something of a dearth of peer-reviewed scientific publications to support the pursuit. This paper is a critical review of the current literature in which we emphasize the weaknesses of the present state of knowledge. Some research directions are proposed to gather statistical knowledge of the within-source and between-source variability of earmarks and earprints. Its ultimate goal is to be able to assess likelihood ratios in relation to this type of evidence.