3D Documentation of a Clandestine Grave: A Comparison Between Manual and 3D Digital Methods
Victoria Berezowski, Jason J. Keller, & Eugene Liscio
Abstract: The purpose of this research was to compare manual and 3D digital methods for documentation of a clandestine grave located at the University of Toronto Mississauga. Measurements were taken using manual trilateration as well as digitally using a total station and a terrestrial laser scanner. Comparisons were made between each method using 14 landmarks on a buried skeletal cast. Twenty-five measurements were taken across the 14 landmarks using Rhino, a 3D modelling software, as well as FARO Scene. These measurements were compared and found an average difference of 1 mm between the total station and the laser scanner measurements, 10 mm between the total station and manual measurements, and 10 mm between the laser scanner and manual measurements. The results provide investigators with an alternative method of clandestine grave documentation that can be more precise as well as being time and personnel efficient on scene.
Supplemental Material: Grave Video
Sniper Target Tracking Analysis of John F. Kennedy Assassination
Nicholas R. Nalli
Abstract: US President John F. Kennedy was assassinated by a sniper while riding in an open limousine in Dallas, Texas on 22 November 1963. Although official investigations established that three shots were fired from a sniper’s nest in the Texas School Book Depository, a complete reconstruction of the sequence of shots was not thoroughly established. Subsequent research has led to a consensus that the first shot missed, but a complete explanation has eluded investigators. This paper presents a quantitative analysis of the sniper targeting effort, including the advantages of the sniper’s nest and eventual marksmanship difficulty. It is quantitatively shown that the three-dimensional target tracking was significantly reduced as the motorcade proceeded away from the sniper’s nest. The reduction in apparent motion of the target correlates with the increasing accuracy of the three shots, suggesting this variable plausibly factored into the enigmatic hit-and-miss pattern.
A Preliminary Validation for the FARO Zone 3D Area of Origin Tool
Abstract: The use of laser scanners and other three-dimensional (3D) technologies to document and analyze bloodstains has been the subject of previous papers, especially where area of origin analysis is concerned. Both HemoSpat and FARO Scene are commonly found in literature where they have been used to provide area of origin analysis for impact stains. The data for this study was collected and analyzed using FARO Zone 3D Software on Wednesday, March 7th, 2018 at the annual Association for Crime Scene Reconstruction (ACSR) conference in Tacoma, Washington, USA. In all, 14 participants analyzed a single bloodstain impact pattern and the accuracy and inter-observer errors were obtained. Overall, it was shown that the average error for all participants was approximately 5.7 cm from the known position. The maximum absolute errors for the x, y, and z axes were 1.1 cm, 3.3 cm, and 4.5 cm, respectively. The standard deviation between examiners was 2.5 cm, 2.1 cm, and 3.1 cm for the x, y, and z axes, respectively.