FBI plans 'Rapid DNA' network for quick database checks on arrestees
Though DNA has revolutionized modern crime fighting, the clues it may hold aren't revealed quickly. Samples of saliva, or skin, or semen are sent to a crime lab by car (or mail), and then chemists get to work. Detectives are accustomed to waiting days or weeks, or more, for the results. Some labs are so backed up, they only take the most serious crimes. Some samples never get tested.