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Trace Metal Detection Techniques in Law Enforcement

NCJ Number
Date Published
October 1970
16 pages
This manual describes the technique for detecting and identifying traces and specific patterns left on suspects' skin and clothing by weapons, tools, and other metal objects.
Research has determined that metal objects leave traces on skin and clothing surfaces in characteristic patterns, with intensities proportional to the interaction of weight, friction, or duration of contact with metal objects. The Trace Metal Detection Technique (TMDT) makes such metal trace patterns visible when skin or clothing is treated with a test solution and then is illuminated by ultraviolet light. The metal trace patterns appear as fluorescent colors on the hands or clothing of the suspect, allowing a police officer to determine whether the suspect has been in contact with certain metal objects, the type of metal or metals in the objects, and what type of object was probably involved. However, physical evidence obtained through the technique should be used as an adjunct to a complete investigation. Photographs and detailed description of equipment and procedures used

Date Published: October 1, 1970