DOI: 10.3886/icpsr28741.v1
title: Tool Mark Analysis of Cut Costal Cartilage, 2009-2010 [United States]
title: Version 1

description: The study was designed to establish the potential error rate associated with the generally accepted method of tool mark analysis of cut marks in costal cartilage. Three knives with different blade types were used to make experimental cut marks in costal cartilage of pigs. Each cut surface was cast, and each cast was examined by three analysts working independently. Presence of striations, regularity of striations, and presence of a primary and secondary striation pattern were recorded for each cast. The distance between each striation was measured. The Cut Mark Measurement Data (Dataset 1) are comprised of the observations and measurements of three analysts on 180 distinct specimen identifiers. The repeated measurements were aggregated by taking the Mean Interstriation Distance (MID) and the medians of the numeric variables for each combination of the categorical variables, resulting in the Aggregated Cut Mark Measurement Data (Dataset 2).
description: The purpose of the study was to test the repeatability of striations impressed into pig (Sus scrofa) costal cartilage by a tool's cutting edge in order to establish the potential error rate associated with the generally accepted method of tool mark analysis of cut marks in costal cartilage.
description: Three knives with different cutting edges (smooth, serrated, and micro-serrated) were used to make experimental cut marks in costal cartilage of pig spare ribs (Sus scrofa). The knives were unused prior to the study. Each knife was used to make 30 cut marks. Three portions of spare ribs were used; only one knife was used per portion. Each knife was held perpendicular to the spare ribs and then forced through the costal cartilage in a ventral to dorsal direction to generate the cut marks. The cut marks were made by an individual other than the analysts. Each cut mark produced two cut surfaces. Therefore, the study design resulted in 180 cut surfaces. Each cut surface was cast, and each cast was examined by three analysts working independently. Each analyst was a doctorate level practicing forensic anthropologist who performs tool mark examination of cut costal cartilage during regular laboratory analysis. Each analyst examined the cut surface and recorded (1) whether striations were present, (2) whether the striations occurred at regular intervals, and (3) whether the striations were organized into a primary and secondary pattern. If striations were present, the analyst measured the distance between each striation. The analysts were blind to the blade type at the time of the analysis. The Cut Mark Measurement Data (Dataset 1) are comprised of 4,195 records of the observations and measurements of three analysts on 180 distinct specimen identifiers. The repeated measurements made by the three analysts were then aggregated by taking the Mean Interstriation Distance (MID) and the medians of the numeric variables (Width, Length, Area) for each combination of the categorical variables (Analyst, Specimen, Striation Pattern, Striation Type, Striations, Blade Type, and Cut Type). This resulted in 535 records, presented as the Aggregated Cut Mark Measurement Data (Dataset 2).
description: The Cut Mark Measurement Data (Dataset 1) are comprised of the following variables: an analyst identifier, a specimen identifier, whether striations are present, striation type (i.e., regular, irregular, or none), the presence of a primary and secondary striation pattern, the blade type of the knife used to create the cut mark (i.e., smooth, serrated, or micro-serrated), whether the costal cartilage was completely transected by the knife, the distance between each striation, and the width, length, and area of the cut surface. The Aggregated Cut Mark Measurement Data (Dataset 2) are comprised of the same variables as the Cut Mark Measurement Data (Dataset 1), except that <em>mean</em> interstriation distance (MID) replaces the distance between each striation.
description: None.
description: Response Rates: Not applicable.
description: Presence of Common Scales: None.
description: Three analysts analyzed 180 cut surfaces in three portions of pig spare ribs, producing 4,195 records for the Cut Mark Measurement Data (Dataset 1) and 535 records for the Aggregated Cut Mark Measurement Data (Dataset 2).
description: Datasets: DS0: Study-Level Files DS1: Cut Mark Measurement Data DS2: Aggregated Cut Mark Measurement Data
description: Observations and measurements of cut marks in costal cartilage of pig (Sus scrofa) spare ribs. Smallest Geographic Unit: None.
description: coded on-site observation