Finally, the evidence is transported to a forensic laboratory. Here, biological samples may be subjected to DNA profiling, while trace evidence like fibers or soil is analyzed under microscopes. The interpretation of these results is the final step in the scientific investigation of a crime scene. In the IELTS Reading test, you will face various question types. For the topic "Investigating A Crime Scene," the most common types are True/False/Not Given , Summary Completion , and Sentence Completion .

Once secured, the investigation is handed over to a specialized team. The lead investigator will usually conduct a "walk-through" to gain an overview of the scene. This is a crucial step where the investigator mentally maps the scene, proposing theories about the events that transpired. During this phase, the path of the investigator is carefully chosen to avoid disturbing potential evidence.

Following the initial survey, the scene is meticulously documented. Photography is the primary tool used here. Photographs are taken from every angle—wide shots to show the scene in context, mid-range shots to show the relationship between pieces of evidence, and close-ups to capture specific details. Alongside photography, sketching is employed. While cameras capture a moment in time, sketches provide spatial measurements and are often easier to present in a courtroom setting.

The IELTS Reading exam is notorious for its diverse range of topics, testing a candidate's ability to comprehend complex texts, identify specific details, and understand the author's intent. One particularly challenging and recurring theme in the IELTS Academic Reading section is forensic science and criminology. A classic example of this is a passage titled "Investigating A Crime Scene."

Only after documentation is complete does the collection of evidence begin. This is a task governed by strict protocols to prevent contamination. Investigators wear protective clothing—not to protect themselves, but to prevent their own hair or skin cells from contaminating the scene. Every item collected is sealed in a container and labeled, initiating the "chain of custody." This legal term refers to the documentation of who has handled the evidence from the moment of collection until it is presented in court. A broken chain of custody can render critical evidence inadmissible, potentially jeopardizing the entire case.