Crime Scene Investigators (CSIs) and Forensic Scientists play distinct roles in the criminal justice process. CSIs work primarily at crime scenes, where they collect, document, and preserve physical evidence such as fingerprints, biological samples, and trace materials. Their focus is on proper evidence handling and maintaining the chain of custody, and they often have backgrounds in law enforcement or criminal justice rather than advanced science degrees. In contrast, Forensic Scientists work in laboratory settings, analyzing the evidence collected by CSIs. They perform specialized scientific tests, interpret results, prepare detailed reports, and frequently testify as expert witnesses in court. These positions require advanced education in scientific disciplines such as chemistry, biology, or forensic science, along with strong analytical and communication skills. In short, CSIs gather evidence in the field, while Forensic Scientists analyze that evidence in the lab.