Chapter 11: Fingerprints

Question 1

What are fingerprints?

Answer 1

• Ridges on toes, fingers, feet & palms
• Raised portions of the skin arranged in connected units called dermal/fricition ridges
• Purpose is to help us grip onto objects

Question 2

4,000 years ago

Answer 2

1st known use as signatures on clay tablets

Question 3

1700

Answer 3

Andreas Mayer 1st noted that no two fingerprints are the same

Question 4

1856

Answer 4

Herschel noted that they didn change w age

Question 5

1879

Answer 5

Bertillion began keeping fingerprints of police files

Question 6

1888

Answer 6

Galton developed the fingerprint classification system in use today

Question 7

1896

Answer 7

The Ten Card was invented allowing them to be used in criminal investigations from then on

Question 8

Arches

Answer 8

• About 5% of all prints
• Have ridges that enter from one side & leave from the other w/ a rise in the center
• Plain arch > shows ridges entering one side/no angle/no pattern

Question 9

Tented Arch

Answer 9

angle/can have a loop pattern/delta

Question 10

Visible/Patent

Answer 10

left on smooth surface when blood, ink, or another liquid comes in contact w/ the hands and is the transferred to the surface

Question 11

Plastic

Answer 11

indentations left in some soft material such as clay, putty or wax

Question 12

Latent/Hidden

Answer 12

caused by the transfer of oils & other body secretions onto a surface. They are made visible b dusting w/ powders or making the fingerprints in some way more visible by using a chemical reaction

Question 13

When do fingerprints form?

Answer 13

10 weeks into pregnancy

Question 14

3 Classes of Fingerprints

Answer 14

loops whirls & arches

Question 15

Loops

Answer 15

• 65% of prints
• Enter from the right or left & leave on the same side
• Has a core at the center and a delta (a triangular region)

Question 16

Whorls

Answer 16

• 30% of all prints - look like a bulls eye w/ 2 deltas
• Plain Whorl - one or more ridges that make a complete spiral/2 deltas

Question 17

Double Loop Whorl

Answer 17

2 separate loop formations w/ 2 deltas

Question 18

Accidental Whorl

Answer 18

2 or more deltas & is the combination of 2 of the other patterns

Question 19

1987

Answer 19

23 mil criminal fingerprint cards collected needed to be manually sorted

Question 20

After 1999

Answer 20

matches in 2hrs

Question 21

What is the AFIS?

Answer 21

FBI developed the Integrated Automated Fingerprint Identification System in 1999

Question 22

What does the IAFIS do?

Answer 22

provides digital automated fingerprint searches, latent searches, electronic storage of fingerprint photo ales, exchange and test results

Question 23

Methods to Visualize Latent Prints

Answer 23

• Ninhydrin
• Super Glue
• Silver Nitrate
• Iodine
• Fluorochromes

Question 24

Ninhyrdrin

Answer 24

can be sprayed on paper. It reacts w/ amino acids in sweat to leave a purple print

Question 25

Super Glue

Answer 25

(Cyanoacrylate)
can be heated in a vapor tent. It sticks to amino acids to get fingerprints in glass, metal, and skin

Question 26

Silver Nitrate

Answer 26

wood or styrofoam objects can be dipped or sprayed w/ silver nitrate. It reacts w/ chloride in the salty sweat to show a print

Question 27

Flurochromes

Answer 27

can be sprayed on non-pourous items and views w/ UV light

Question 28

Iodine

Answer 28

can be heated in a vapor tent or a fuming gun to get prints off of paper, cardboard, and unpainted surfaces. It fades and must be photographed

Question 29

What type of fingerprints need to be developed?

Answer 29

Latent

Question 30

How do Children’s and Adults Prints Differ?

Answer 30

Children have shorter fatty acids and therefore evaporate quicker

Question 31

Composition of Residue Left by a Latent Print

Answer 31

99% water, 1% fatty acids, salts, etc

Question 32

What time span in which childrens fingerprints can be detected?

Answer 32

24hrs