(YA) This is a chatty, anecdotal survey of scientific detection. The cases used to illustrate the application of laboratory principles to criminal evidence are mostly American, although British contributions to forensic medicine, pathology allistics, etc. are also noted. The equipment of investigation has become as ophisticated as that in internal medicine. The way in which the instruments are used and how the methods of their use were developed makes for entertaining reading with the subliminal preventive message -- violence is futile and highly detectable.