LECTURE 13: FINGERPRINTS // CHAPTER

Question 1

Individual characteristics

Answer 1

• fingerprint ridges
• tool marks
• specific paint/ surface preparations
• specific wear patterns on tires/ shoes
• material that can be fitted together to make a whole

Question 2

class characteristics

Answer 2

• can only be associated with general type
• paint scrapings from auto accidents
• sharp, knife-like instrument
• impressions from car/truck badges
• type of can used to make a homemade explosive device
• value is that it corroborates other evidence
• place individual at the scene
• drives a particular type of car

Question 3

types of prints

Answer 3

• fingerprints
• foot, ear, hand
• eye, iris
• tyre
• shoe
• bitemarks
• toolmarks

Question 4

types of finger prints

Answer 4

Latent
- not visible to the naked eye
- need to use some form of visualtion technique
visible
- formed when an appropriate substance (e.g. paint, blood, ink, soot) is transferred by the finger tips to a suitable surface
plastic (or moulded)
- formed when the print is impressed into a soft material e.g. wax, chocolate, clay, fresh pain

Question 5

visualising latent prints

Answer 5

Powders
-	black, gray, coloured, magnetic 
-	used on non-porous surfaces
-	need to ensure contrast between powder colour and background
chemicals 
-	ninhydrin / dfo spray 
-	lawsone
-	cyanoacrylate fuming
-	physical developer (silver nitrate AgNO3 based)
spectroscopy
-	sometimes able to detect print directly as compounds in the print produce fluorescence
-	e.g. micro X-ray fluorescence 
combinations
-	typically chemical and fluorescence 
-	becoming more common

Question 6

friction rides appear on

Answer 6

palms, soles, ends of fingers and toes

Question 7

friction ridges begind forming in

Answer 7

9th or 10th week of fetal development

Question 8

primary friction ridge develop

Answer 8

develop deep in dermal layer of skin, until 15th or 17th week of gestation

Question 9

secondary friction ridge develop and mature when

Answer 9

develop week 17 and mature week 24

Question 10

loops

Answer 10

have 1 or more ridges entering from 1 side of the print, curving back on themselves, & exiting the fingertip on the same side.

Question 11

ulnar loop

Answer 11

o If the loop enters & exits on the side of the finger toward the little finger

Question 12

radial loop

Answer 12

o If the loop enters & exists on the side toward the thumbv

Question 13

type lines

Answer 13

All loops are surrounded by 2 diverging ridges

Question 14

delta

Answer 14

The point of divergence

Question 15

core

Answer 15

central portion of the loop

Question 16

arches

Answer 16

rarest of the 3

Question 17

plain arch

Answer 17

ridges entering 1 side of the finger, gradually rising to a

rounded peak, & exiting the other side.

Question 18

tended arch

Answer 18

arches with a pronounced, sharp peak. A pattern that
resembles a loop but lacks one of the required traits to be classified
as a loop can also be designated as a tended arch.

Question 19

arches dont have

Answer 19

type lines, cores, deltas

Question 20

whorls

Answer 20

have type lines & at least 2 deltas

Question 21

whorls divided into 4

Answer 21

plain whorl, central pocket loop, double loop, & accidental

Question 22

central pocket loops and plain whorls

Answer 22

have a minimum of one ridge that is continuous around the pattern, but this ridge does not necessarily have to be in the shape of a circle – can be an oval, ellipse, or a spiral.

Question 23

plain whorls

Answer 23

are located between the 2 deltas of the whorl pattern

Question 24

double loop

Answer 24

is made up of 2 loops that swirl around each other.

Question 25

accidental whorls

Answer 25

is a pattern that combines 2 or more patterns (excluding
the plain arch) and/or does not clearly meet the criteria for any of the
other patterns.