The investigation of a crime scene begins when the CSI unit receives a call from the police officers or detectives on the scene. II. The CSI arrives on the scene and makes sure it is secure. A. He/she does an initial walk-through to get an overall feel for the crime scene B. Finds out if anyone moved anything before he/she arrived C. Generates initial theories based on visual examination D. He/she makes note of potential evidence. At this point, he/she touches nothing. III. The CSI thoroughly documents the scene by taking photographs and drawing sketches during a second walk-through. A.
The documentation stage includes a video walk-through B. He/she documents the scene as a whole and documents anything identified as evidence IV. Now it’s time to touch stuff—very, very carefully. A. The CSI systematically makes his/ her way through the scene collecting all potential evidence, tagging it, logging it and packaging it so it remains intact on its way to the lab. B. Depending on the task breakdown of the CSI unit he/she works for and his/her areas of expertise, he/she may or may not analyze the evidence in the lab. V. The crime lab processes all of the evidence the CSI collected at the crime scene.
When the lab results are in, they go to the lead detective on the case. Conclusion I. Every CSI unit handles the division between field work and lab work differently. II. What goes on at the crime scene is called crime scene investigation (or crime scene analysis), and what goes on in the laboratory is called forensic science. Not all CSIs are forensic scientist. III. Some CSIs only work in the field—they collect the evidence and then pass it to the forensics lab. In this case, the CSI must still possess a good understanding of forensic science in order to recognize the specific value of various types of evidence in the field.