Crime Scene Searching Methods PDF

The Crime Scene The crime scene is the beginning point for obtaining evidence, which will be used by the crime scene investigation team and forensic experts. A thorough investigation of the crime scene must be completed. Discuss It! What are some potential erro...

The Crime Scene The crime scene is the beginning point for obtaining evidence, which will be used by the crime scene investigation team and forensic experts. A thorough investigation of the crime scene must be completed. Discuss It! What are some potential errors that could be made by investigators when working the crime scene? The Crime Scene A crime scene tells a story. Investigating the scene is meant to begin the process of answering questions like: What has happened? Who did it? How did they do it? Why did they do it? Crime scenes can be classified by the location of the crime. Primary crime scene (the initial location) Ex. A victim is killed at their home. Secondary crime scene (a secondary location) Ex. Killer disposes of a victim in the woods after killing them at their home. Both the primary and secondary crime scenes should be searched thoroughly. Searching The Crime Scene  The goals of the crime scene search are to recognize, document, collect, and preserve evidence.  Following proper protocol and procedures at crime scenes include legally obtaining access to the scene.  In the US, the fourth amendment requires that to enter any place (to search for and/or seize evidence), the authorities must have a warrant.  A search warrant is a warrant to search a specific premise for evidence of a specific crime.  The warrant is issued by the judge/magistrate if he or she finds probable cause to believe such evidence exists based on information presented by police to the judge in the form of a signed affidavit. Searching The Crime Scene  Experienced crime scene investigators understand that there is no single ideal way to search a crime scene.  A combination of skills, training, experience, and intuition will guide the investigator in choosing which crime scene search method to use.  There are four major search patterns that are typically used:  Line/Strip  Spiral  Grid  Zone/Quadrant Line/Strip Method  The line/strip method is a pattern used to search relatively large areas.  In a line search, a square area is divided into parallel strips or lanes with one searcher per lane.  The searchers slowly walk a straight line through the middle of the lane and visually cover the full width of their lane.  This method is one of the easiest to employ and work well in large, open areas (i.e.: Spiral Method  The spiral method of crime scene searches requires investigators to view the scene as a circle.  The spiral can begin at a specific point and spiral outward or start on a perimeter and spiral inward. The width of the spirals depends on the circumstances but should be narrow enough to ensure complete visual coverage. Grid Method  The grid method is a modified version of the line (strip) search method.  Once an area has been searched by the line (strip) method, the area is searched perpendicular to the original lines of search, so that both sets of lines (if they were overlaid) would form a grid.  While this is more time-consuming than the line method, it is more comprehensive and has the additional benefit of each section being searched by more than one person. Zone/Quadrant Method  The zone/quadrant method divides the crime scene area into logical zones that can be individually searched by investigators.  Indoor crime scenes are good places to employ the zone method. Searching The Crime Scene  During the search, investigators mark evidence with evidence identification markers.