Footwear marks

Question 1

What is a footwear mark examiner involved in?

Answer 1

examination of footwear and tyre marks

identification of comparison footwear and tyre marks

enhancement of marks

recovery of trace evidence

Question 2

Name 3 issues with footwear mark impressions.

Answer 2

difficult to locate at scene

not a biometric in itself

no database of the owner of every shoe

unlikely to give rapid results

Question 3

What two techniques can we use to assist with footwear mark impressions?

Answer 3

gait analysis

Cinderella fit

Question 4

Name 5 patterns of shoe soles.

Answer 4

zig-zags
blocks
circles
polygons
bars

Question 5

What are the 4 classes of impression?

Answer 5

positive
negative
plastics/3D
various miscellaneous which do not fit into above catergoies

Question 6

What is a positive impression?

Answer 6

residue from the sole is deposited into a surface

Question 7

What are positive impressions most discernible on?

Answer 7

smooth non-porous surfaces

can be liquid or dry residues

Question 8

What is a negative impression?

Answer 8

the sole removes material from a surface

Question 9

What are patent marks?

Answer 9

discernible under normal lighting

Question 10

What are latent marks?

Answer 10

may only be visible under certain lighting types or from certain angles

Question 11

What are plastic 3D impressions?

Answer 11

a shoe deforms a softer surface to produce a 3D mark

variable in quality as dependant upon material texture and stability

Question 12

What is the problem with kicking or stamping marks?

Answer 12

difficult medium to work from due to the elasticity of skin

Question 13

What do you need to be aware of when studying bruises or lacerations?

Answer 13

these may develop over time

Question 14

Name 6 enhancement techniques?

Answer 14

Chemical - elect colour change

powders

ESLA

gel lift

alternative light source

specialist photography

Question 15

Name 3 ways to recover 2D footwear marks?

Answer 15

photography

may require chemical development

lifting

Question 16

Name 3 ways to recover 3D footwear marks?

Answer 16

photography

may require chemical development

casting

Question 17

Gel lifts

Answer 17

dust marks
non porous surfaces
gel lifts-black, white, clear
sealed with acetate sheet

Question 18

Name 5 enhancement techniques?

Answer 18

ninhydrin
leach crystal violet
Hungarian red
acid yellow
bluestar

Question 19

What is ELSA?

Answer 19

electro static lifting apparatus
can be used on floors
foil sheet
electrical current applied

Question 20

What is used to cast 3D footwear marks?

Answer 20

dental stone

Question 21

What are the two classifications of scene marks?

Answer 21

static

dynamic

Question 22

What are 4 things that are compared when looking at footwear marks?

Answer 22

pattern
size
wear
damage

Question 23

What are basic class characteristics?

Answer 23

repeatable characteristics shared by many or all shows of the same type or class

Question 24

Wear characteristics

Answer 24

caused by way individual walks

wear patterns generally do not constitute positive ID as two individuals can be shown to produce almost identical patterns

short lived Shallamach wear (feathering) is something very different from general wear and is considered to be unique

differences could be due to wear/degradation since crime mark produced

Question 25

What are identifying characteristics?

Answer 25

random events giving rise to a unique characteristic found on only this shoe

Question 26

what are the three types of lighting/illumination?

Answer 26

transmitted = through a surface

coaxial = reflective surfaces

oblique = useful for different types of marks, lighting from the side