<p>If Locard’s Exchange Principle is the cornerstone of forensic science, evidence is the heart and soul of the crime lab. Indeed, evidence is the sole reason it exists. Without evidence, what would the lab do? Evidence is used to determine if a crime has been committed, to link a suspect to a scene, to corroborate or refute an alibi or statement, to identify a perpetrator or victim, to exonerate the innocent, to induce a confession, and to direct further investigation.</p>