59 lines
3.2 KiB
Plaintext
59 lines
3.2 KiB
Plaintext
June 1990
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FOCUS ON FORENSICS:
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LATENT SHOEPRINT ANALYSIS
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For decades, fingerprints have provided investigators
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invaluable clues to establish the identity of criminals. Yet,
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another type of print impression that could be just as valuable
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has been widely overlooked. Latent shoe prints exist in almost
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all interior crime scenes but are often ignored by investigators
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or destroyed by initial responders before the prints could be
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processed.
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Latent shoe prints are impressions of shoe treads left by an
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individual on a surface. While these prints cannot be seen by
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the naked eye, they can be revealed using standard fingerprint
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powders. Although investigators routinely search for visible
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shoe prints on interior surfaces and shoe impressions in
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exterior crime scenes, they often overlook the existence of
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latent shoe prints.
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Like fingerprints, latent shoe prints can be used to place a
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suspect at a crime scene. Though each shoe manufacturer produces
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hundreds of various styles of footwear with the same tread
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design, these identical prints quickly become unique through the
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owner's use. Wear will vary depending on individual walking
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styles and contact with different surfaces. Any scratch, nick or
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cut will result in points of comparison, making the shoe ``one of
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a kind.''
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Most casual shoes have rubberized soles that, when exposed
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to light amounts of moisture, react in a way similar to a finger
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leaving its mark on a surface. Vinyl linoleum, smooth tile, and
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painted floors provide the best surfaces for recovery of latent
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shoe prints.
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Many of the same factors that are involved in lifting
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fingerprints are to be considered in recovering latent shoe
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prints. The surface must be smooth enough to reveal the
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characteristics of the soles. Temperature and weather conditions
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must be conducive to preservation of the impressions. And, like
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fingerprints, latent shoe prints are fragile and can be damaged
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if further contact is made after the print is placed. They can
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be easily altered or destroyed by first responders and curious
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bystanders; therefore, it is important to carefully secure the
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crime scene if recovery of the prints is to be successful.
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Latent shoe prints have not been widely used in crime scene
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investigations. Although recovery of the prints depends on
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several unpredictable variables, they may yield valuable
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information and, therefore, should be considered a viable option
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for investigators.
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____________
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Information for this column was provided by Dwain A.
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Pierce, Criminalistics Specialist, Police Department, Knoxville,
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Tennessee.
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