title: Virtual and simulated striated toolmarks for forensic applications.
abstract: Large numbers of experimental toolmarks of screwdrivers are often required in casework of toolmark examiners and in research environments alike, to be able to recover the angle of attack of a crime scene mark and to determine statistically meaningful properties of toolmarks respectively. However, in practice the number of marks is limited by the time needed to create them. In this article, we present an approach to predict how a striated mark of a particular tool would look like, using 3D surface datasets of screwdrivers. We compare these virtual toolmarks qualitatively and quantitatively with real experimental marks in wax and show that they are very similar. In addition we study toolmark similarity, dependent on the angle of attack, with a very high angular resolution of 1°. The results show that for the tested type of screwdriver, our toolmark comparison framework yields known match similarity scores that are above the mean known non-match similarity scores, even for known match differences in angle of attack of up to 40°. In addition we demonstrate an approach to automatically recover the angle of attack of an experimental toolmark and experiments yield high accuracy and precision of 0.618 ± 4.179°. Furthermore, we present a strategy to study the structural elements of striated toolmarks using wavelet analysis, and show how to use the results to simulate realistic toolmarks.
authors.affiliation: Department of Microtraces, Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB Den Haag, The Netherlands. Electronic address: m.baiker@nfi.minvenj.nl.
authors.forename: Martin
authors.initials: M
authors.lastname: Baiker
authors.affiliation: Department of Sciences, John Jay College of Criminal Justice, City University of New York, 524 West 59th Street, New York, NY 10019, United States.
authors.forename: Nicholas D K
authors.initials: ND
authors.lastname: Petraco
authors.affiliation: Department of Sciences, Borough of Manhattan Community College, City University of New York, 199 Chambers Street, New York, NY 10007, United States.
authors.forename: Carol
authors.initials: C
authors.lastname: Gambino
authors.affiliation: Department of Microtraces, Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB Den Haag, The Netherlands.
authors.forename: René
authors.initials: R
authors.lastname: Pieterman
authors.affiliation: Department of Mathematics and Computer Science, John Jay College of Criminal Justice, City University of New York, 524 West 59th Street, New York, NY 10019, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Shenkin
authors.affiliation: Department of Microtraces, Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB Den Haag, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Zoon
mesh_terms: D066264:Datasets as Topic; D044707:Forensic Sciences / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D012984:Software; D058067:Wavelet Analysis; D054041:Weapons; D014950:Wounds, Penetrating / Q000473:pathology*
keywords: 3D tool models; Objective comparison; Striated toolmarks; Toolmark variability; Virtual and simulated toolmarks; Wavelet based multiscale analysis