Forensics U3: Fingerprints

Question 1

What are the fundamental principles of fingerprints?

Answer 1

1. Unique characteristics make them individual evidence
2. Consistent over a person’s lifetime
3. Systematically classified

Question 2

Describe the formation of fingerprints

Answer 2

Ridges and Valleys

Question 3

The purpose of fingerprints is to…

Answer 3

link a portion of a crime scene to an individual.

Question 4

Prints are also found:

Answer 4

Using the AFIS (Automated Fingerprint Identification System)

Question 5

Fingerprints cannot be removed because…

Answer 5

the ridges of skin that create a fingerprint run deep.

Question 6

Fingerprinting is __________ evidence, meaning it puts you ___ ___ ________ ______.

Answer 6

physical

at the crime scene

Question 7

Describe the use of fingerprints in investigations.

Answer 7

Comparing fingerprints found at a crime scene and linking them back to the shared fingerprint owner.

Question 8

Ridgeology

Answer 8

The study of the uniqueness of friction ridge structures and their use for personal identification.

Question 9

A fingerprint is made of a series of _______ ____ ________.

Answer 9

ridges and furrows

Question 10

The uniqueness of a fingerprint can be determined by ____ _________ of ridges and valleys as well as the ____________ _________, which are points where the ridge structure changes.

Answer 10

the pattern

minutiae points

Question 11

Describe the importance of identifying minutiae in a case.

Answer 11

Used to determine the uniqueness of a fingerprint image.

Question 12

How many points of similarity do the US and international courts accept for a match?

Answer 12

8 out of 12

Question 13

Describe AFIS (Automated Fingerprint Identification System) and its importance.

Answer 13

Stores and retrieves fingerprints, the AFIS searches files for a set of prints and compares a single print from a crime scene.

Question 14

AFIS

Answer 14

Automated Fingerprint Identification System

Question 15

Other than fingerprints, describe other prints that are accurate in linking a suspect to a crime scene.

Answer 15

Palm
Lip
Voice
Shoe
Foot
Eye
Teeth

Question 16

Describe the importance of a latent print.

Answer 16

It can link a suspect to a crime scene.

Provide proof of contact.

Identify people that may not previously have been known.

Question 17

Describe the type of print development listed below:

Powders/dusting

Answer 17

Adheres to both water and fatty deposits, Choose a color to contrast with the background, Best on hard, nonabsorbent surfaces, Develop print by “lifting” with clear sticky tape.

Question 18

Describe the type of print development listed below:

Iodine

Answer 18

Fumes react with oils and fats to produce a temporary (short lasting) yellow-brown colored print, Works best on porous paper.

Question 19

Describe the type of print development listed below:

Ninydrin

Answer 19

Reacts with amino acids to produce an orange to purple color,
Best with paper, tissue, clothing and other porous surface.

Question 20

Describe the type of print development listed below:

Silver Nitrate

Answer 20

Reacts with chloride in salt to form silver chloride, This will turn into silver oxide (gray) when exposed to light, Best for porous substances like paper and drywall.

Question 21

Describe the type of print development listed below:

Cyanoacrylate

Answer 21

Superglue fumes react with water and other fingerprint constituents to form a hard, whitish deposit , This can then be treated with powders or fluorescent dyes to make a sharper contrast for photos or lifting.