Final answer:
The Principle of Exchange, stating that 'every contact leaves a trace', is attributed to Dr. Edmond Locard, a key figure in forensic science.
Step-by-step explanation:
The Principle of Exchange is a forensic concept that states that 'every contact leaves a trace'. This principle is fundamentally attributed to Dr. Edmond Locard, who is often referred to as the father of modern forensic science. According to this principle, whenever two objects come into contact, there is always a transfer of material. This concept is the cornerstone of much forensic science, especially in the field of crime scene investigation, where traces of physical evidence such as fibers, hair, or skin cells are exchanged between the perpetrator, the victim, and the scene.