Crime scene search patterns
Crime scene search patterns are structured geometric methods employed by investigators to systematically locate and collect evidence at a crime scene. These patterns are vital for maximizing the chances of finding critical evidence while minimizing disturbance to the scene itself, which could compromise the integrity of the evidence. Various templates are available for investigators, including the spiral, strip, wheel, and zone patterns, each suited to different types of environments and scenarios.
The spiral pattern involves searching outward or inward from a central point, making it useful for scenes where evidence is concentrated in a particular location. The strip pattern divides the area into narrow sections, allowing searchers to move in coordinated lines, ideal for expansive outdoor locations. The wheel pattern features spokes radiating from a central point, enabling simultaneous searches across defined sections without cross-contamination. Finally, the zone pattern subdivides areas into quadrants, facilitating focused searches, particularly in complex environments like buildings.
These search methods can also be adapted for underwater investigations, which present unique challenges such as visibility and physical obstacles, requiring divers to use specific techniques to ensure thorough coverage. Overall, employing systematic search patterns is crucial for effective evidence collection and maintaining the integrity of a crime scene investigation.
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Subject Terms
Crime scene search patterns
DEFINITION: Geometric template method used to search for evidence at a crime scene.
SIGNIFICANCE: The orderly approach of following a geometric pattern in the search for and gathering of evidence at a crime scene maximizes discovery efforts and minimizes the disturbance of evidence prior to discovery.
Law-enforcement investigators organize their searches of crime scenes to maximize the likelihood of finding evidence and to minimize the likelihood that they will fail to discover existing evidence. The discovery process itself should not cause undue disturbance of the scene, as this could cause evidence to be damaged or overlooked. To organize their searches, investigators choose from various geometric templates, which are then imposed on the scenes to be searched; four commonly used templates are the spiral, the strip, the wheel, and the zone pattern. Evidence discovery points at a can be diagrammed at corresponding points on a paper or digital record that serves as a blueprint of the crime scene.
A emanates from a center point and travels in widening curves from that point like a coiled snake. The search path may begin from either end of the spiral. For example, a bloody knife found on the street would most likely generate a spiral search path starting at the location of the knife (center of the spiral) and working outward. A crime scene with a victim inside a room having a single doorway would probably generate a spiral search pattern that starts from the doorway (outer end of the spiral) and works inward, toward the center.
A strip (or linear) search pattern divides a crime scene into long, narrow sections. Investigators may begin an evidence search at either end of the strip. This sort of search is often used across large land areas to look for evidence such as the presence of a person in that vicinity. In a typical strip pattern search, searchers walk shoulder to shoulder or separated by an arm’s length in a line that moves simultaneously across an area.
The wheel pattern search has a center point from which spokes radiate outward to connect to a circle enclosing the search area. The sections of the wheel pattern search thus are shaped like slices of a pie. Searchers can investigate sections simultaneously from the outer perimeter toward the center without crossing or disturbing possible evidence in other sections. The wheel pattern search may be used when time for searching is limited, such as when adverse weather conditions make it likely that the crime scene will soon be disturbed.
The zone (or grid) search pattern uses perpendicular lines that form square search areas (quadrants); each quadrant can be further divided into smaller quadrants pertinent to the search. Crime scene investigators who need to search buildings often do so by dividing each floor into zones. Zoned investigations may quickly rule out particular zones that are not pertinent to the crime, thus freeing investigators to concentrate on the zones that do contain evidence.
An underwater crime scene may use the same search patterns. However, such sites present unique challenges, such as poor visibility, underwater obstacles, and dangers to divers. Search patterns typically use search lines (ropes) to ensure divers cover the area thoroughly and maintain the same distance from a central spot or while crossing back and forth in a search area.
Bibliography
Fisher, Barry A. J., and David R. Fisher. Techniques of Crime Scene Investigation. 9th ed. CRC Press, 2022.
Genge, N. E. The Forensic Casebook: The Science of Crime Scene Investigation. New York: Ballantine, 2002.
Pentland, Peter, and Pennie Stoyles. Forensic Science. Philadelphia: Chelsea House, 2003.
Platt, Richard. Crime Scene: The Ultimate Guide to Forensic Science. New York: Dorling Kindersley, 2003.
Rymansaib, Zuhayr, et al. "A Prototype Autonomous Robot for Underwater Crime Scene Investigation and Emergency Response." Journal of Field Robotics, vol. 40, no. 5, 2023, pp. 983-1002, doi.org/10.1002/rob.22164. Accessed 14 Aug. 2024.