FIS 201 Exam 3 Set 1: Lectures 16–17 — Fingerprints

What are friction ridges?

Raised lines on the skin of the fingers, palms, toes, and soles of the feet.

When do friction ridges begin developing?

Around the fourth month of fetal development.

Do friction ridge patterns change throughout life?

Their general patterns remain consistent, although size can change and scars can alter ridge details.

What is a latent fingerprint?

A hidden or not immediately visible fingerprint that requires development.

What is a patent fingerprint?

A fingerprint that is immediately visible, such as one made in blood, ink, or grease.

What is a plastic fingerprint?

A three-dimensional fingerprint impression left in a soft material such as wax, clay, or soap.

What substances can leave fingerprints?

Sweat, oils, and other skin secretions.

What is a porous surface?

A surface that absorbs liquids, such as paper or cardboard.

What is a nonporous surface?

A surface that does not readily absorb liquids, such as glass, metal, or plastic.

How does fingerprint dusting work?

Powder adheres to oily fingerprint residue, making the print visible.

What tools can be used for fingerprint dusting?

A fiberglass brush or magnetic brush.

What is one disadvantage of fingerprint dusting?

Excessive brushing or powder can damage or obscure a fingerprint.

Why photograph a fingerprint before lifting it?

To preserve its original appearance before lifting could damage or distort it.

What is fingerprint lifting tape used for?

Transferring a developed fingerprint from a surface onto a lift card.

What is cyanoacrylate fuming?

A fingerprint development method that uses cyanoacrylate vapor to form a polymer on fingerprint residue.

What surfaces are commonly treated with cyanoacrylate fuming?

Nonporous surfaces, such as glass, metal, and plastic.

What does a fingerprint developed with cyanoacrylate often look like?

White or pale and ghostlike.

Why apply fluorescent dye after cyanoacrylate fuming?

To improve fingerprint visibility and contrast against the background.

What is ninhydrin used for?

Developing latent fingerprints on porous surfaces, especially paper.

What does ninhydrin react with?

Amino acids in sweat.

What color does ninhydrin produce?

Purple, known as Ruhemann's purple.

What is gentian violet used for?

Developing fingerprints on adhesive surfaces, such as the sticky side of tape.

What is leucocrystal violet (LCV) used for?

Enhancing fingerprints associated with blood.

What do amido black, Coomassie blue, and Hungarian red have in common?

They are protein stains that can be used for appropriate blood-related evidence.

Why can textured surfaces be difficult for fingerprint lifting?

Their uneven surfaces make it difficult for tape to contact the entire fingerprint.

What materials can help recover impressions from textured surfaces?

Flexible materials such as Mikrosil or polyvinylsiloxane.

What is a ten-print card?

A record containing fingerprints from all ten fingers.

What is Live Scan?

Electronic collection of fingerprint images.

Who was Alphonse Bertillon?

A criminologist who developed Bertillonage, a system based on body measurements for personal identification.

What was Bertillonage?

A personal identification system based on standardized body measurements.

What were disadvantages of Bertillonage?

It was awkward, time-consuming, and expensive.

What did William Herschel contribute to fingerprint history?

He used fingerprints on contracts in India during the nineteenth century.

What did Henry Faulds contribute to fingerprint history?

He wrote about fingerprints in Nature in 1880 and discussed their permanence and collection.

What did Sir Francis Galton contribute to fingerprint science?

He published Fingerprints in 1888, classified patterns, and studied minutiae.

What are the three basic fingerprint patterns?

Arches, loops, and whorls.

What is a fingerprint arch?

A pattern in which ridges enter from one side and exit from the other, with no deltas.

What is a fingerprint loop?

A pattern in which ridges enter and exit on the same side, generally with one delta.

What is a fingerprint whorl?

A pattern that is generally circular or spiral and typically has two or more deltas.

How many deltas does an arch have?

Zero.

How many deltas does a loop generally have?

One.

How many deltas does a whorl typically have?

Two or more.

What is the core of a fingerprint?

The approximate central area of a fingerprint pattern.

What is a fingerprint delta?

A triangular or Y-shaped region where ridge flows diverge.

What are minutiae?

Small ridge characteristics used to compare fingerprints.

What is a ridge ending?

A point where a fingerprint ridge stops.

What is a bifurcation?

A point where one fingerprint ridge splits into two.

What is a known fingerprint?

A fingerprint associated with a known or documented source.

What is an unknown fingerprint?

A fingerprint recovered from evidence whose source must be determined.

What does ACE-V stand for?

Analysis, Comparison, Evaluation, Verification.

What happens during the analysis stage of ACE-V?

The examiner assesses print quality and determines whether enough detail is available for comparison.

What happens during the comparison stage of ACE-V?

The examiner compares ridge characteristics, minutiae, and their relative positions.

What happens during the evaluation stage of ACE-V?

The examiner reaches an identification, exclusion, or inconclusive conclusion.

What happens during the verification stage of ACE-V?

A second examiner checks the examination and conclusion.

What does identification mean in fingerprint comparison?

The examiner concludes that the prints originate from the same source.

What does exclusion mean in fingerprint comparison?

The examiner determines that the prints do not originate from the same source.

What does inconclusive mean in fingerprint comparison?

There is insufficient information to reach a confident identification or exclusion.

What does AFIS stand for?

Automated Fingerprint Identification System.

What is AFIS used for?

Searching fingerprint databases for potential matches.

What fingerprint features can AFIS analyze?

Ridge endings, bifurcations, relative feature positions, and ridge-flow direction.

Does AFIS independently establish a final fingerprint identification?

No. It generates potential candidates that require examiner evaluation.

What is IAFIS?

Integrated Automated Fingerprint Identification System, the name associated with the FBI's earlier integrated fingerprint system.

What are common criticisms of fingerprint comparison?

Some conclusions involve subjective judgment and can be affected by contextual information or examiner bias.

Why are verification and documentation important in fingerprint examination?

They help improve quality control, transparency, and reliability.