1. Forensic Footwear Evidence
Chapter 18
Forensic Footwear Evidence
Page 341

2. What information can you gather from this foot?

3. What is Forensic Footwear Evidence?
Physical contact between footwear and a viable surface leaves a transfer of class and individual characteristics, which can be used in identification of possible suspects
P 361

4. Forms of Footwear Impressions
=Those that remain after a shoe has permanently deformed a surface.
=Those patent or latent prints left on a non-giving surface.
Two Forms
Three Dimensional Impressions
Two Dimensional Impressions
P 362

5. Forms of Footwear Impressions
Note: Very often the less visible impressions actually retain greater detail than those that result from heavier deposits of residue, dust, or blood.
Sand
Mud
Snow
Three Dimensional Impressions
Wood/Paper
Glass
Carpet
Two Dimensional Impressions
P 362

6. Information from Footwear Impressions1
Positive ID of footwear 2
Elimination of Footwear 3
Location of Impressions and association with other evidence 4
Rebuttal or Confirmation of a suspect’s alibis 5
Determination of shoe brand/manufacturer
--Proving a suspect’s presence at a crime and thus possible participation in the crime
--Based o CLASS characteristics changes in or absence of random individual characteristics are normally not used to eliminate a shoe
--Can help lead to uncovering other impressions or physical evidence
--Aided by use of FBI footwear database that includes thousands of shoe designs
P 362

7. Information from Footwear Impressions6
Determination of shoe size 7
Gait characteristics 8
Linking of crime scenes 9
Number of perpetrators 10
Tracking
--Recording dimen-sions of impressions can allow for general estimate of shoe size
--Refers to how someone walks
--Measurements from impressions include stride, step width, and walking pace
--Note: not reliably used as a means of personal ID
--Databases can store footwear impressions recovered from scenes and can be used to find a matches or links between different crimes (helpful with repetitive crimes like burglaries)
-- More than one print design found can suggest the # of people who potentially committed the crime
--Observing impression series that can result in following the path of an individual (ex illegal aliens and kidnapped children)
P 362

8. Number of perpetrators?
Tracking
Determination of Shoe Size
Association with Other Evidence
Identification of Footwear ?

9. Video Duration~1:28

10. Location and Recovery of Footwear Impressions
1. CS Security:
Important to secure crime scenes as soon as possible to prevent other impressions being tracked over the evidence
2. Location:
Some impressions easily located (i.e. bloody or muddy)
Most require more effort to locate
Use alternative light source or electrostatic lifting device
Use clues in environment as a place to look (i.e. entrance and exit points, and paper, magazines, or glass on floor which often hold latent prints in good detail)
3. Recovery
next slide

11. Recovery (cont.) Starts with notes and photographs (# cards in photo)
Take mobile prints to lab
Prints that cannot be moved and may need to be enhanced.
1. Examination quality photography
directly over print, 35 mm film, ruler in picture
oblique/UV/infrared lighting for contrast
possible use of chemicals to enhance before photo (ex. leuco crystal violet, amido 10 black, luminal)
2. Lifting 2-D prints
Electrostatic—used for dry origin impression
Fingerprint powder
3. Casting 3-D prints
Use dental stone, a gypsum product
Stronger than plasters and provided quicker and easier recovery P

12. Two – Dimensional Impressions
Recovery (cont.)
Two – Dimensional Impressions
Once an impression has been photographed, the print may be able to be lifted
Electrostatic lifting transfers
Fingerprint powder in combination with mikrosil may be used on impressions where electrostatic lifting does not work
Electrostatic Lifting Film This foil backed black mylar produces exceptional detail in even the most subtle dust impressions
P 367

13. Electrostatic Lifting Device
Text and image from: Introduction to Criminalistics: The Foundation of Forensic Science
 By Barry A. J. Fisher, William J. Tilstone, Catherine Woytowicz

14. Three – Dimensional Impressions
Recovery (cont.)
Three – Dimensional Impressions
Dental stone is primary means of casting footwear impressions
On wet surfaces, a spray wax may have to be used first to seal impression
Mix dental stone with water in a ziplock bag for 3 minutes
Stone hardens in 20 minutes
In hours it will have fully hardened
P 368
Pre-Measured Dental Stone

15. Enhancement Methods
Poor impressions may have to be enhanced by one of the following means:
NOTE: Enhancement similar to fingerprints
Forensic Photography
Oblique, ultraviolet, infrared lighting
Physical Methods Latent powder, lifting impressions
Chemical Methods Reagents such as leuco crystal violet, amido 10 black, or luminol
Digital Methods Software such as Adobe Photoshop can be used to enhance impressions
P 368

16. Recovered print Analysis:
Need to have known shoes and exemplars to compare against
Footwear from Suspected Persons:
All footwear a suspect owns should be seized for comparison
Shoes are needed to make test impressions
P 370

17. Known Shoes and Preparation of Exemplars
Known Test Impressions of Footwear- Examiner will make impressions of known footwear and compare them with suspected footwear impression to insure matching samples are highly detailed, and have individual characteristics of shoes
Elimination Footwear – Footwear worn by police officers, medical personnel should be accounted for when considering impressions left at scene
P 371

18. The Examination Process and Conclusions
Areas of footwear which are examined by analyst include:
Design of shoe
Physical Size and Shape
Wear marks
Individual Identifying Characteristics- cuts tar, gum etc
P 372

19. Quia Quiz