Historically, in the cases of criminal poisoning, the most decisive element of expert medico-legal knowledge was chemical evidence. This, more than any other method, enabled the toxicologist, to claim with a high degree of probability that a poisoning took place. The ability to provide chemical proof in a case of criminal poisoning was a crucial feature of the toxicologist’s suite of expertise because it thwarted the design of one unique feature of the criminal act, that of concealing the instrument of violence as is insidiously common. Most of all, the power of chemical proof lay in its capacity to ‘demonstrate’ to a legal audience via extracting and demonstrating poison from the body of the victim. The maneuvers of toxicologists to bring poison from ‘invisible’ to ‘visible’ in the body of the victim allowed the law to judge — with enough circumstantial evidence at hand — the accused as guilty or not guilty. Aesthetics was translated into, and transferred over to the conditions for a judgment to emerge.
In forensic presentations of evidence, making the trace of a crime visible is not mere information but is a matter of persuasion. As a presentation to the senses, it is persuasive of judgment. In Western jurisprudence the corpus delicti (the body of the crime) refers to the principle that a crime must be proven to have occurred before a person can be convicted of committing that crime. Invoked in murder investigations, the best evidence for establishing crime is the body of the deceased and the cause of death. In this sense, the term also describes the evidence that proves that a crime