Robert O’Brien, a detective assigned to the 28th Security Forces Squadron, gathers a sample of blood at a simulated crime scene at Ellsworth Air Force Base, S.D., Nov. 10, 2016. Once collected, samples are sent to the U.S. Army Criminal Investigation Labs where they are run for DNA before being sent to the Federal Bureau of Investigation to determine a match. (U.S. Air Force photo illustration by Airman 1st Class Donald C. Knechtel)