Digital image cross-correlation technique for bite mark investigations

Many techniques of bite mark analysis have been described using direct comparisons, overlays and replication methods, but all opinions are based on subjective assessments. This study aimed to produce a non-interactive method of bite mark comparison using a digital image correlation technique to remove operator subjectivity. An image of a real injury and suspect dental casts were digitally processed and passed through a correlation algorithm. This yielded figures representing correlation coefficients between the image of the mark and the dentition of the suspects. An image was displayed demonstrating a particular suspect cast in maximum correlation with the injury. This system was also applied to an artificial mark set. In the real mark series, the highest correlation was noted for an individual not involved in the incident. The reasons and implications of the findings are discussed.