Crime Scene Considerations: Electronic Control Device (TASER®) Deployment
R.T. Wyant, M.S., Tom Burns & Kathy Geil
Abstract: The demand for law enforcement to have access to less lethal tools has never been higher. Within the last ten years, products from TASER® International have dominated the marketplace and are now in use in more than 16,000 police agencies worldwide. As investigators, scientists, and crime scene analysts, Electronic Control Devices (ECD) such as TASERs will be encountered in casework. Their role, capabilities, and limitations must be understood to properly collect and analyze the evidence involved. These devices and their components can be analyzed to determine proper function, establish a hit or a miss, and in some cases determine the duration of shock to assist in the reconstruction of a field “failure” or in custody death.
PDF: Crime Scene Considerations: Electronic Control Device (TASER) Deployment
Detecting Blood in Soil after Six Years with Luminol
Ron Gabel, Denver Police Department (CO), Sheri Shimamoto, Lakewood Police Department (CO), Ivanie Stene, Westminster Police Department (CO), and Tom Adair
Abstract: In October of 2004 the authors began a study to examine the possibility of detecting blood in soil over extended periods of time. A sample grid was created on a hilltop at the Highlands Ranch Law Enforcement Training Facility located in Douglas County, Colorado (USA). The sample grid is comprised of six 24″x24″ (61x61cm) units in which 500ml of neat horse blood was poured in an “X” pattern. Subsequent studies have shown that a recognizable “X” pattern persisted up to 16 months and that blood can be detected at the site up to four years following deposition. This paper presents another extension of that detection up to six years.
Detecting Patched Bullet Holes in Painted Drywall
Tom Adair & Charles S. DeFrance
Abstract: Reconstructionists must sometimes deal with crime scene evidence that has been cleaned, moved, or repaired. The extent of these alterations can greatly impair efforts to understand the events surrounding the commission of a crime. In the worst of scenarios, repairs or alterations to the evidence will effectively render it “undetectable”. Such is the case with patched bullet holes. This paper examined three non-destructive methods for detecting patched bullet holes in drywall.
Digital Mapping of Differential Oxidation Arising from Fingerprint Sweat Deposits on α-Phase Brass
John W. Bond, Scientific Support Unit, Northamptonshire Police, Wootton Hall, Northampton, England and Trudy Loe, Scientific Support Unit, Northamptonshire Police, Wootton Hall, Northampton, England
Abstract: Visualization of differential oxidation on phase brass, subject to heating to temperatures of up to 600°C, is shown to be enhanced by selective digital mapping of colors reflected from the surface of the brass using Adobe® Photoshop®. Enhancement is optimal when the brass is heated to ~250°C with areas of oxidation having a mirror like appearance. The use of this enhancement method to visualize fingerprint sweat deposits on brass cartridge cases is demonstrated.
PDF: Digital Mapping of Differential Oxidation Arising from Fingerprint Sweat Deposits on α-Phase Brass
Off the Grid: Perspective Grid Photogrammetry in Crime Scene Reconstruction
Julie Flanagan & Edward Robinson
Abstract: Photogrammetry, the practice of obtaining accurate measurements from a photograph, is a technique nearly as mature as photography. One of the most rudimentary forms, perspective grid photogrammetry, utilizes an object of known dimensions within the photograph to determine the spatial relationships of evidence in the photograph. By measuring the location of two points, each piece of evidence captured within a photograph may be extrapolated. This enables on scene crime scene investigation work to be completed in a fraction of the time typically required using baseline or triangulation measurements. Spending less time measuring can be advantageous for those crime scenes located in war zones, in situations in which bad weather will disrupt the crime scene, or whenever the time at the crime scene must be minimized.
PDF: Off the Grid: Perspective Grid Photogrammetry in Crime Scene Reconstruction
The Evolution of Crime Scene Reconstruction from Proto-analysis to Holistic Analysis: A Court Case that Assisted in this Evolution
Tom Bevel, Bevel, Gardner & Associates, Inc. and ACSR Historian
Abstract: In 1992 a double murder in El Paso County, Colorado took the lives of Kermode and Pamela Jordan. Physical evidence strongly implicated one juvenile, but failed to establish guilt for his juvenile accomplice. The statements by both boys were ruled inadmissible, which led the District Attorney to pursue a crime scene analysis and reconstruction expert to explain to the jury that one attacker could not accomplish all of the events that took place during the crime.
Using a Holistic Approach to Completing an Investigation
Jonathyn W. Priest
Abstract: A challenge for the law enforcement officer is ensuring a complete and thorough investigation. Complete investigations do not depend on a single characteristic or lone investigative technique. The complete investigation requires the multiple disciplines and abilities of the investigative team. Adequate crime scene analysis and reconstruction, forensic testing, effective interview and interrogation, and analytical skills each contribute to the whole investigation. When investigators ignore or neglect procedures, discontinue or slow an inquiry upon arresting an offender, or fail to examine all aspects of a case, they might not realize the victory of a successful prosecution. Investigators frequently experience feelings of accomplishment during the beginning of an investigation, the efforts to get resolution, and ultimate capture of a suspect. Occasionally, however, the investigator has a sensation similar to the one of elation, but it is actually desolation. This unfortunately occurs when a case fails at trial secondary to an inadequate or incomplete investigation.
Visualization of Cast-off Patterns Using 3D Modelling Software
Andy Maloney, FORident Software and Todd Campbell & Jim Killeen, Ottawa Police Service
Abstract: Information gathered from cast-off patterns can be quite difficult to communicate to others who may not have attended the scene. An analyst at the scene can often visualize where in the room the person was standing when they were swinging the bloodied object that created the pattern as well as the approximate plane of motion of the swing. This information may be used as a limiting factor in their reconstruction, but the current methods of recording and conveying this information are limited. This paper demonstrates that more information can be gathered through an analysis of cast-off and presents a technique to record, analyze, and describes a technique to communicate it to others using a 3D software model.
PDF: Visualization of Cast-off Patterns Using 3d Modelling Software