Crime scene measurement
Crime scene measurement is a critical investigative process involving the precise recording of the locations of all elements within a crime scene, including evidence and relevant items. This meticulous documentation allows investigators to recreate the scene accurately for further examination or courtroom presentation. Following the identification of a crime scene, items found must be tagged, numbered, and photographed while detailed measurements are taken. These measurements utilize fixed points—such as buildings or curbs—to avoid reliance on movable objects, ensuring accuracy in the item's positioning.
Methods like the rectangle method are often employed for precise measurements, which are essential for later reproducing the scene accurately. Innovative technologies, including geographic information systems (GIS) and laser scanners, are increasingly used to enhance this process. Ultimately, the ability to recreate crime scenes not only aids in investigations but also supports legal proceedings by providing a clear visualization of the evidence as it was originally found.
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Subject Terms
Crime scene measurement
DEFINITION: Precise recording of the exact locations of all elements of a crime scene, including all items found there and all evidence collected.
SIGNIFICANCE: The accurate recording of all measurements of a crime scene, particularly the locations of the various items found there, enables investigators to reproduce the scene at a later date, so that they can examine each item in relationship to the others and to the overall scene.
After a has been identified and then documented, the found there must be located, numbered, tagged, and photographed, and the scene must be measured in detail. This procedure allows investigators to reproduce the scene later with all items of evidence and other important items depicted. This reconstruction, made to scale, may take the form of a detailed sketch; it may be used for investigative purposes, for courtroom presentation, or both. A three-dimensional reproduction of the crime scene may also be made to assist jurors in visualizing the scene as it was found. Photographs are helpful, but they are limited because they are two-dimensional and do not indicate the exact locations of all the items present and the relationships among the items.
When a crime scene is measured, sophisticated mathematical models are used to ensure that each item is measured from a fixed point to reposition in its exact location at a later date. It would not be helpful, for example, to position an item found in the street by measuring its position in relation to a car parked next to the curb, because the car will be moved at some point. The position of an item in the street should be measured from something that will not move, such as a piece of curb or a point on a building. For a crime scene in a house, a measurement could be made from a specific point on a given wall.
Using the example of a crime scene in the street, a measurement could be made from curb prolongations (usually employed in traffic accident investigations) or other fixed objects, such as buildings or power poles. For example, at the scene of a shooting in which investigators find an expended twelve-gauge shotgun shell in the street, a method of positioning the shell could be used. The notes on such a measurement might read as follows:
Evidence item 1: One 12-gauge shotgun shell, Remington Express, 3″ mag, red, expended. Found in the center of First Street, south of Los Osos Blvd. Shell was 22′ southeast of ConEd Power Pole #3216, located on the southwest corner of First St. and Los Osos Blvd. and 29′8″ southwest of the northwest corner of Bean’s Café located at 1608 First St., Big City.
The items noted can be cross-referenced with crime scene photographs.
Using the example of a gun found on the floor of a room, the measurements could be made from the walls of the room:
Evidence item 6: Gun, S&W blue steel revolver, 4″ barrel, Mod 28, serial number unknown. Found 6′3″ south of the north wall of bedroom number 3 and 18″ from the west wall of said bedroom.
In this example, two right angles are employed to fix the exact position of the gun on the floor of the bedroom; this is frequently referred to as the rectangle method.
In crime scene measurement, the most critical issue is precision. All measurements must be exact, so that the crime scene can later be reproduced accurately, with all items placed where they were found. Many law-enforcement agencies have begun to employ computer programs designed to assist in this endeavor. Geographic information systems (GIS) and laser scanners can be used to measure crime scenes and document the locations of evidence at sites.
Bibliography
Gilbert, James N. Criminal Investigation. 6th ed. Upper Saddle River, N.J.: Pearson Prentice Hall, 2004. Print.
Mokwena, Rakgetse John, and M. G. Makola. "Digitalisation of Crime Scenes Investigation Using Geographic Information System Photogrammetry in South African Police Services." International Journal of Social Science Research and Review, vol. 6, no. 2, 2023, pp. 472-482, doi.org/10.47814/ijssrr.v6i2.1051. Accessed 14 Aug. 2024.
O’Hara, Charles E., and Gregory L. O’Hara. Fundamentals of Criminal Investigation. 7th ed. Springfield, Ill.: Charles C Thomas, 2003. Print.
Weston, Paul B., and Charles A. Lushbaugh. Criminal Investigation: Basic Perspectives. 9th ed. Upper Saddle River, N.J.: Prentice Hall, 2003. Print.