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.