FORS-2107EL Study Guide - Quiz Guide: O. J. Simpson Murder Case, Hydraulic Press, Gelatin
27 Jun 2018
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Footwear Quiz Review
-Footprints are the second most common type of evidence type, after DNA
-Useful in burglary, assault, robbery, rape or homicides
-A positive impression is 2 dimensional, and occurs when someone transfers matter (like dust
or blood) from their shoe to the surface they walk on
-A negative impression is 3 dimensional, and occurs when the shoe removes residue from the
surface it walks on (ex. mud or cement)
-The first time footprints were used an investigation was in 1816, in a homicide of a maid
-This was also used in the OJ Simpson trial where they found a blood footprint
-Class characteristics: brand, make, outsole pattern, design features, all help to find the
manufacturer of the shoes
-Individual characteristics: manufacturing irregularities, holes in tread, wear on the shoe, rocks
can make holes and indentations
-Wear patterns occur from gradual wearing away of rubber due to friction between the surface
the sole of the shoe
-When walking, people always place a certain part of their foot down first, then the rest
follows, so wear will be more pronounced where the foot lands first
-Wear on the outside rear near the heal, is supinate (walking with ankles turned out, away
from the other foot)
-Wear on the inside of the shoe towards toes, is pronate (walking with the ankle turned in,
towards the other foot)
-Wear that is uniform around the front would be neutral (with foot coming into contact with
found evenly)
-When analyzing a footprint, there is not a minimum number of characteristics needed, as long
as the characteristics found were clear, detained and defined, and had significant features in
common with the impression
-Other things that can be found from footprints: direction, sex, movement
-Men walk with their toes pointed straight forward, while women walk with mor pigeon toed
with smaller strides
-Deep prints that had front pressed in more and longer stride, indicates a faster pace of
walking
-Depth of prints can indicate weight of person
-Prints that are deeper on one side means someone was carrying something on that side
-Stride length and width can also be looked at, to find height, in combination of foot size, as
foot length is approximately 15% of a persons height
-Footprints can be visualized by shining a bright oblique light in a dark room, when they are
not visible alone
-3-D prints are lifted by castings, and may need to be prepped prior to lifting (ex. adding
hairspray to sand to harden it, or pipetting water out of mud)
-2-D prints can be lifted by using a hydraulic press and gelatine lifters (a strip with adhesive on
it)
-Normally a gelatine lifter alone can be used on non porous surfaces, like glass, or wood
flooring , but if the surface is porous then a press will be needed, like in cardboard or fabric
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Footprints are the second most common type of evidence type, after dna. Useful in burglary, assault, robbery, rape or homicides. A positive impression is 2 dimensional, and occurs when someone transfers matter (like dust or blood) from their shoe to the surface they walk on. A negative impression is 3 dimensional, and occurs when the shoe removes residue from the surface it walks on (ex. mud or cement) The rst time footprints were used an investigation was in 1816, in a homicide of a maid. This was also used in the oj simpson trial where they found a blood footprint. Class characteristics: brand, make, outsole pattern, design features, all help to nd the manufacturer of the shoes. Individual characteristics: manufacturing irregularities, holes in tread, wear on the shoe, rocks can make holes and indentations. Wear patterns occur from gradual wearing away of rubber due to friction between the surface the sole of the shoe.
