Page 15 - The Shoe Must Fit Footprint Analysys

hidden may be visualized. Care must be taken film. The film is then placed over the impression
by the crime teams not to disturb the evidence where the charge causes the matter forming the
left by the criminal. If enough time and effort is impression to cling to the film. Prints can be lifted
administered, most surfaces will surrender a print. from almost any surface in this manner, including
a human body. Very rarely are criminals careless
When considering the vast variety of surfaces that enough to leave prints made of mud. These
yield prints, it has become necessary to develop would require much effort from the crime scene
multiple techniques to lift the prints with the least technicians in lifting the prints.
amount of distortion. Before the print is lifted,
photography is an essential step of any crime Depending upon the surface and location the
scene investigation as it provides visual evidence print was left, forensic investigators may have a
of the original footprint. A photograph will depict narrow window in which to lift the print. Prints left
the footprint in relation to the crime scene, allowing in blood may last for years, whereas prints left in
investigators to view the complete scene after all of water may evaporate, and prints made with sand
the evidence has been collected. Three-dimensional may be brushed away. Realizing this complication,
footwear impressions are most often lifted by many forensics experts do not take the time
casting. Casting, or taking a mold of the impression, required to properly gather prints. Prints from
will provide a true-to-size physical model of the police officers and others on the scene may mix
print. When there is worry that the print might be with the prints from the criminal complicating the
disturbed by the pouring of the casting material, process. If patience and care are executed, prints
the surface is first prepped. For prints deposited in that have been layered with the prints of others
sand, forensic scientists will spray the print with an at the crime scene may be lifted. Multiple prints
aerosol glue or even aerosol hairspray. Water can be may even be lifted at once with a gel lifter. Pages
drawn away from the surface of a muddy print by of gel are placed down gently on the surface and
using a lab instrument called a pipette, followed by a then numbered to retain their sequence. Additional
hot air source, such a hair dryer. Once the print has pages are then placed down and taped to other
been prepped and a frame placed around the print, pages. Forensics experts are then able to recreate
the casting material is poured into the impression. the footsteps at a remote location.

Two-dimensional prints are found on surfaces such A person interested in a forensics career in
Two-dimensional prints are found on surfaces such footprint analysis should seek a bachelor’s degree
as glass, wood flooring, cardboard, or fabric and from an accredited four-year college with a major
may be lifted using a hydraulic press and gelatin in criminalistics, chemistry, biology, or physics.
lifters or electrostatic devices. Gelatin lifters are To prepare for this, it is recommended that a high
sheets of paper with a strong adhesive on one school student should pursue classes with an
side that lift the print from most surfaces. More emphasis on sciences and mathematics. Traits
porous surfaces, such as cardboard or fabric, would of patience and perseverance also prove very
require the use of a hydraulic press to push down beneficial to someone interested in footprints
on the gelatin and, thus, enable a print to be lifted forensics. The American Academy of Forensic
in clarity. Electrostatic devises are good for lifting Sciences provides a website with a list of colleges
prints from hard to access areas, such as carpeting, and universities providing forensic degree
wood, and fabric. The electrostatic device uses programs. For more information, visit this website:
a highvoltage power unit to charge a metallic www.aafs.org.

THE MYSTERY OF LYLE AND LOUISE 15