In October of 2004 six testing grids were created on a hilltop at the Highlands Ranch Law Enforcement Training Facility located in Douglas County approximately eleven miles south of Denver, Colorado (USA). Each grid unit measured 24 x 24 in (61 x 61cm). The authors poured 500 ml of neat horse blood into each grid unit at the commencement of the study to test the effectiveness of using the blood reagent luminol to detect the blood pattern and presence over prolonged exposure. The testing was originally expected to last no more than 24 months. This study marks the eighth year of successful blood detection at this site using luminol.