Tool Mark Analysis of Cut Costal Cartilage, 2009-2010 [United States] (ICPSR 28741)
Version Date: Sep 16, 2014 View help for published
Principal Investigator(s): View help for Principal Investigator(s)
Jennifer Love, Harris County (TX) Institute of Forensic Sciences;
Sharon Derrick, Harris County (TX) Institute of Forensic Sciences;
Jason Wiersema, Harris County (TX) Institute of Forensic Sciences;
Charles Peters, University of Houston
https://doi.org/10.3886/ICPSR28741.v1
Version V1
Summary View help for Summary
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).
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Subject Terms View help for Subject Terms
Geographic Coverage View help for Geographic Coverage
Smallest Geographic Unit View help for Smallest Geographic Unit
None.
Distributor(s) View help for Distributor(s)
Time Period(s) View help for Time Period(s)
Date of Collection View help for Date of Collection
Study Purpose View help for Study Purpose
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.
Study Design View help for Study Design
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).
Sample View help for Sample
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).
Time Method View help for Time Method
Universe View help for Universe
Observations and measurements of cut marks in costal cartilage of pig (Sus scrofa) spare ribs
Unit(s) of Observation View help for Unit(s) of Observation
Data Source View help for Data Source
Observations and measurements of cut marks in costal cartilage of pig (Sus scrofa) spare ribs completed by three analysts
Data Type(s) View help for Data Type(s)
Mode of Data Collection View help for Mode of Data Collection
Description of Variables View help for Description of Variables
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 mean interstriation distance (MID) replaces the distance between each striation.
Response Rates View help for Response Rates
Not applicable.
Presence of Common Scales View help for Presence of Common Scales
None.
HideOriginal Release Date View help for Original Release Date
2014-09-16
Version History View help for Version History
- Love, Jennifer, Sharon Derrick, Jason Wiersema, and Charles Peters. Tool Mark Analysis of Cut Costal Cartilage, 2009-2010 [United States]. ICPSR28741-v1. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2014-09-16. http://doi.org/10.3886/ICPSR28741.v1
2014-09-16 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:
- Created variable labels and/or value labels.
- Standardized missing values.
- Checked for undocumented or out-of-range codes.
Notes
The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.