What does Locard's Exchange Principle state regarding trace evidence?

Locard's Exchange Principle is a fundamental concept in forensic science that asserts that whenever two objects come into contact, there is an exchange of materials between them. This means that when a person interacts with a scene, whether through touching, moving objects, or being present, they will leave behind trace evidence, and may also pick up trace evidence from the scene.

The statement that all items leave a trace captures this idea perfectly. It emphasizes the importance of trace evidence, which can include hair, fibers, skin cells, or any other minute materials that may be transferred during contact. This principle underscores the notion that even small or seemingly insignificant evidence can be vital in a criminal investigation, as it can link a suspect to a crime scene or victim. Understanding this principle is crucial for crime scene analysts as they work to meticulously collect and analyze trace evidence, which often plays a pivotal role in solving cases.