Vanishing Blood Stains: Determining the optimum apparel fabric and residential lighting conditions for a bloodstain to disappear
Date
2020
Authors
Sullivan, Brittni
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Abstract
Bloodstain Pattern Analysis (BPA) is one of the most important forensic crime scene techniques to date. Fluid dynamics with blood remain relatively similar across the board, which is why many researchers remain focused on specific patterns and what they can reveal about the movements of contributors in a scene. As a bloodstain pattern analyst becomes more proficient in the identification of certain stains, the advanced analyst will begin to study the effect of blood on fabrics. It is well known within the field of BPA that Alternate Light Sources (ALS) are required in most scenes containing blood evidence. This researcher sought to identify which specific fabrics (color and composition) best mask blood stains under residential lighting conditions. Determining the fabric which best disguised a given blood stain will prove useful to the Crime Scene Technician (CST) as well as the subsequent litigation team. If a person alleged they observed “bloody clothing” on a subject/victim, this research answered whether this observation was possible to the untrained eye. Additionally, the results sought to determine the optimum fabric type, pattern, and color to best disguise blood on apparel fabric at a scene. When the “optimum fabric” was observed at a given crime scene with potential blood evidence, this research would trigger the crime scene technician to utilize an ALS, as well as submit the item for in-depth analysis at the laboratory. A sample of fabrics was tested using recent statistics of U.S. consumption of fabric. This ensured an equal sampling of the general American population, and included various solid color and printed fabrics. Additionally, the sample fabrics included various military uniforms (Army Multicam, Marine Combat Utility Uniform, Navy Working Uniform, and Airman Battle Uniform) to make the study relevant to the Department of Defense. The various fabric types and patterns provided different qualities with the respective blood stains that were subsequently measured to gain quantitative results. The fabric samples were placed in four separate indoor lighting conditions, and the contrast of the stains were objectively measured and determined there was no significant difference between each light source. This research ultimately determined there was a significant difference between the construction and color of the fabric.
Description
Keywords
Bloodstains, Blood forensics, Apparel
Citation
Sullivan, B., (2020). Vanishing bloodstains: Determining the optimum apparel fabric and residential lighting conditions for a bloodstain to disappear. George Mason University. Fairfax, Virginia.