June 1990                                         
                                                                  
                      FOCUS ON FORENSICS:                                
                   LATENT SHOEPRINT ANALYSIS                      
                   
                                               
     For decades, fingerprints have provided investigators 
invaluable clues to establish the identity of criminals.  Yet, 
another type of print impression that could be just as valuable 
has been widely overlooked.  Latent shoe prints exist in almost 
all interior crime scenes but are often ignored by investigators 
or destroyed by initial responders before the prints could be 
processed.                                                        

     Latent shoe prints are impressions of shoe treads left by an 
individual on a surface.  While these prints cannot be seen by 
the naked eye, they can be revealed using standard fingerprint 
powders.  Although investigators routinely search for visible 
shoe prints on interior surfaces and shoe impressions in 
exterior crime scenes, they often overlook the existence of 
latent shoe prints.                                               

     Like fingerprints, latent shoe prints can be used to place a 
suspect at a crime scene.  Though each shoe manufacturer produces 
hundreds of various styles of footwear with the same tread 
design, these identical prints quickly become unique through the 
owner's use.  Wear will vary depending on individual walking 
styles and contact with different surfaces.  Any scratch, nick or 
cut will result in points of comparison, making the shoe ``one of 
a kind.''                                                         

     Most casual shoes have rubberized soles that, when exposed 
to light amounts of moisture, react in a way similar to a finger 
leaving its mark on a surface.  Vinyl linoleum, smooth tile, and 
painted floors provide the best surfaces for recovery of latent 
shoe prints.                                                      

     Many of the same factors that are involved in lifting 
fingerprints are to be considered in recovering latent shoe 
prints.  The surface must be smooth enough to reveal the 
characteristics of the soles.  Temperature and weather conditions 
must be conducive to preservation of the impressions.  And, like 
fingerprints, latent shoe prints are fragile and can be damaged 
if further contact is made after the print is placed.  They can 
be easily altered or destroyed by first responders and curious 
bystanders; therefore, it is important to carefully secure the 
crime scene if recovery of the prints is to be successful.        

     Latent shoe prints have not been widely used in crime scene 
investigations.  Although recovery of the prints depends on 
several unpredictable variables, they may yield valuable 
information and, therefore, should be considered a viable option 
for investigators.                                                
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     Information for this column was provided by Dwain A. 
Pierce, Criminalistics Specialist, Police Department, Knoxville, 
Tennessee.