We report on the experimental detection of blood on exposed concrete over a period of 428 days in the city of Aurora, Colorado. Neat (undiluted) blood was poured in an x- shaped pattern in each grid unit. The x-shaped pattern was chosen as a means of validating any reaction with possible false-positive properties of the substrate as well as to gauge how much deterioration of the pattern may occur over time, if any. Visible luminol reactions of the x-shaped pattern were detected from 14 to 156 days of exposure to the elements. A novel technique for extending this time frame using image enhancement is also discussed which extended the detectable reaction to 295 days.
Visual Appearance and Chemical Detection of Bloodstains on Concrete After Exposure to the Elements
Shimamoto, S; DeFrance, CS; Adair, TW. Visual Appearance and Chemical Detection of Bloodstains on Concrete After Exposure to the Elements. J. Assoc. Crime Scene Recon. 2013, 19(2), 17-27.