Throughout this text, one particular theme will be evident: physical evidence has greater power and ability than testimonial evidence in defining what happened at any crime. This is not to say that testimonial evidence should be ignored or excluded, but an understanding of physical evidence will provide an objective foundation for any subsequent theory of the crime. Physical evidence is what it is, and it is tangible. Presented with deoxyribonucleic acid (DNA) evidence from the scene or a photograph of the condition of the scene, only a fool would argue that the DNA was not really there or that the scene looked other than as depicted in the photograph. To gauge testimonial evidence, all we have is our perception of the individual. Does she or he appear honest? Did she or he have the ability to perceive what she or he reported? Any witness is capable of unconsciously misperceiving events or, for that matter, purposely misrepresenting events based upon some personal agenda. This is a well-established fact in the study of criminal investigation. Understanding this, we do not exclude testimonial evidence, but we certainly seek corroboration of testimonial evidence through some objective means. That means is called crime scene analysis, which is the end result of any effort directed at crime scene processing. The more physical evidence recovered, the more likely a functional and objective theory of what transpired during the crime will be forthcoming.