Understanding the visibility of blood on dark surfaces: A practical evaluation of visible light, NIR, and SWIR imaging. (December 2015)

• Record Type: Journal Article
• Authors: Schotman, Tom G.; Westen, Antoinette A.; van der Weerd, Jaap; de Bruin, Karla G.
• Is Part Of: Forensic science international. Volume 257(2015)
• Page Start: 214
• Page End: 219
• Publication Date: 2015-12
• Subjects: Bloodstain pattern analysis -- Blood -- Infrared -- Textile -- Fabric -- Photography; Medical jurisprudence -- Periodicals; Chemistry, Forensic -- Periodicals; Forensic Medicine -- Periodicals; Médecine légale -- Périodiques; Chimie légale -- Périodiques; Gerechtelijke geneeskunde; Gerechtelijke chemie; Gerechtelijke psychiatrie; Chemistry, Forensic; Medical jurisprudence; Electronic journals; Periodicals; Electronic journals; 614.1
• DOI: 10.1016/j.forsciint.2015.08.024
• Languages: English
• ISSNs: 0379-0738

Abstract

Highlights: 166 dark fabrics were examined regarding the possibility of bloodstain visualization. Bloodstains on most of the textiles could be visualized by means of SWIR imaging due to the spectral properties of the fabric. Both spreading properties and roughness of the textile also play a role in the visualization of bloodstains. A textiles' label can provide information whether or not NIR or SWIR imaging is useful. Abstract: Bloodstains on dark surfaces are often difficult to detect due to a lack of contrast. Infrared photography is in many cases a solution as it enhances the contrast between blood and background. Still, on some surfaces bloodstains cannot be visualized. In this study, we investigate why bloodstains on certain surfaces are not detected and how visibility can be improved. Bloodstains on 166 dark fabrics were photographed by four different cameras and for each, the visibility of the bloodstains was scored. The spectral properties of the dark fabrics were examined as well as the properties of the dyes used to colour the textiles. In addition, spreading of the blood within the textile and the roughness of the material were taken into account. In the investigated set of textiles, visibility of blood is mainly determined by the spectral properties of the textile dye. In addition, a high surface roughness of the textile reduces the visibility.