title: Microscopic analysis of sharp force trauma in bone and cartilage: a validation study.
abstract: Sharp force trauma research lacks agreement on reported error rates for correctly identifying toolmark characteristics on bone and cartilage. This study provides error rates for determining blade class (serrated, partially serrated, nonserrated) and type of edge bevel (left, right, even). Three analysts examined cuts to a wax medium, cartilage, and bone using two types of microscopes. Additionally, the observers examined impressions taken from the wax medium and the cartilage. Overall, a total of 504 observations were performed. Serrated blades were distinguishable from nonserrated blades due to their patterned striations. Some difficulties were encountered in distinguishing serrated and partially serrated blades; however, when these groups were considered together as one classification type (serrated), classification accuracy improved from 79% to 96%. Classification accuracy for edge bevel was 65%. Error rates were similar when comparing direct observation of the cut marks versus indirect observation (impressions). Additionally, the type of microscope used did not affect error rates.
authors.affiliation: Department of Pathology, New York City Office of Chief Medical Examiner, 520 First Avenue, New York, NY, 10016.
authors.forename: Christian
authors.initials: C
authors.lastname: Crowder
authors.affiliation: Department of Pathology, New York City Office of Chief Medical Examiner, 520 First Avenue, New York, NY, 10016.|Department of Anthropology, Center for the Study of Human Origins, New York University, 25 Waverly Place, New York, NY, 10003.|New York Consortium in Evolutionary Primatology, New York, NY.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Rainwater
authors.affiliation: Department of Pathology, New York City Office of Chief Medical Examiner, 520 First Avenue, New York, NY, 10016.
authors.forename: Jeannette S
authors.initials: JS
authors.lastname: Fridie
mesh_terms: D001842:Bone and Bones / Q000293:injuries* / Q000473:pathology; D002356:Cartilage / Q000293:injuries* / Q000473:pathology; D018732:Forensic Anthropology; D049429:Forensic Pathology; D006801:Humans; D008853:Microscopy; D008954:Models, Biological; D015588:Observer Variation; D054041:Weapons / Q000145:classification*; D014951:Wounds, Stab / Q000473:pathology*
keywords: forensic anthropology; forensic science; knife wound; sharp force trauma; stab wound; striations; toolmarks