Introduction Evidence is the key component to solving a crime. Collecting evidence is important because all the questions that cannot be answered by people can be answered in science. Crime scene investigators can be trusted as expert witnesses due to their field experience and knowledge of the evidence. There are two main types of evidence that can be used in court: direct and circumstantial. Direct Evidence Direct evidence is evidence that can be collected at a crime scene by investigators, such as: video, audio, DNA, fingerprints, weapons, and even the bodies of victims. During evidence collection, the scene must be cleared and protected from contamination by other people. It can take investigators several hours to collect evidence and understand the crime scene. Direct evidence is based on facts. “An eyewitness to an event is direct evidence, but eyewitnesses are often unreliable… People may lie or not see things as clearly as they think, especially if an event occurs quickly or in a time of high stress ” (Circumstantial ve...