Campus Units

Materials Science and Engineering, Ames Laboratory

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

7-2015

Journal or Book Title

Journal of Forensic Sciences

Volume

60

Issue

4

First Page

878

Last Page

884

DOI

10.1111/1556-4029.12759

Abstract

A blind study to determine whether virtual toolmarks created using a computer could be used to identify and characterize angle of incidence of physical toolmarks was conducted. Six sequentially manufactured screwdriver tips and one random screwdriver were used to create toolmarks at various angles. An apparatus controlled tool angle. Resultant toolmarks were randomly coded and sent to the researchers, who scanned both tips and toolmarks using an optical profilometer to obtain 3D topography data. Developed software was used to create virtual marks based on the tool topography data. Virtual marks generated at angles from 30 to 85° (5° increments) were compared to physical toolmarks using a statistical algorithm. Twenty of twenty toolmarks were correctly identified by the algorithm. On average, the algorithm misidentified the correct angle of incidence by −6.12°. This study presents the results, their significance, and offers reasons for the average angular misidentification.

Comments

This is the peer-reviewed version of the following article: Spotts, Ryan, L. Scott Chumbley, Laura Ekstrand, Song Zhang, and James Kreiser. "Angular Determination of Toolmarks Using a Computer‐Generated Virtual Tool." Journal of Forensic Sciences 60, no. 4 (2015): 878-884, which has been published in final form at DOI: 10.1111/1556-4029.12759. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

Copyright Owner

American Academy of Forensic Sciences

Language

en

File Format

application/pdf

Published Version

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