“While every crime scene is unique, outdoor scenes are especially challenging because agents have to work against the clock, as the elements change the nature of evidence over time,” said Clayton Drown, a special agent and OSI Det. 631 commander. “JBER conservation officers taught us blood drops in snow can be carried off by scavenging birds or a gust of wind, direct sunlight can change a footprint in snow, and a bullet casing could become difficult to recover.” To mitigate these unique problems, the exercise focused on three techniques: how to find bullet casings, how to cast foot and tire prints, and how to collect a blood sample all left behind in Alaska’s dry snow. Dry snow is powdery and easily blown around by wind.