Fingerprint Test Review

Topics on Your Test! Identify types of fingerprints left at a scene based upon description Latent, plastic, visible Chemical development techniques Superglue, Silver Nitrate, Iodine, Ninhydrin Which technique is best for different surfaces Identify general ridge pattern Whorl, Loop or Arch Identify minutiae Compare prints to determine if they are the same or different and give explanation to your determination Primary Classification AFIS

What is the study of fingerprints?

Dactyloscopy is the study of fingerprints.

When do fingerprint ridges form?

In the womb approximately 10. 5 weeks estimated gestational age In the womb approximately 10.5 weeks estimated gestational age. It is thought that the movement of the fetus is what contributes to the unique ridge characteristics. At only 10 weeks your babies heart is almost completely developed. An opening at the atruim of the heart and the presence of a bypass valve divert much of the blood away from the lungs, Your baby's blood is oxygenated through the placenta and the bypass valve of his heart directs most of his blood away from the lungs (this is automatically reversed when your child is born). Your babies teeth are now forming in the gums. By now his vocal chords are complete. Your baby can now even suck his thumb! The brain is fully formed, and your child can feel pain. This animation represents the currently accepted theory that localized cellular proliferations grow together into what subsequently appear as ridges at the epidermal / dermal junction at approximately 10.5 weeks estimated gestational age.

What is the first fundamental principle of the fingerprint system?

First Principle: A Fingerprint is an Individual Characteristic; No two fingers have yet been found to possess identical ridge characteristics.

How is the individuality of a fingerprint determined?

This individuality of a fingerprint is not determined by its general shape or pattern but by a careful study of its ridge characteristics, also known as minutiae.

Will a fingerprint change during the life of an individual?

Second Fundamental Principle of Fingerprints: Second Fundamental Principle of Fingerprints: A Fingerprint will remain unchanged during an individual’s lifetime.

What is the third fundamental principle of the fingerprint system?

Third Principle: Fingerprints have general ridge patterns that permit them to be systematically classified. All fingerprints are divided into three classes on the basis of their general pattern: Loops, Whorls, and Arches. These three classes form the basis for all 10-finger classification systems.

Definitions of Ridge Characteristics

What is the point at which a friction ridge ends or begins?

Ridge Ending

What is a friction ridge that diverges or “forks”?

Bifurcation

What is a very small portion of a friction ridge?

Dot

What is a small flatter portion of a friction ridge?

Short Ridge

What is it called when a dot or short ridge have ridges on either side of them?

Island

Which minutiae or ridge characteristic occurs when a friction ridge bifurcates (forks) and then converges (joins back together) to form a continuation of a single ridge?

Enclosure

Which Ridge Characteristic am I?

Bifurcation

Which Ridge Characteristic am I?

Dot

Which Ridge Characteristic am I?

Spur

Which Ridge Characteristic am I?

Bridge

Which Ridge Characteristic am I?

Ridge Ending

Which Ridge Characteristic am I?

Island or Short Ridge

Which Ridge Characteristic am I?

Eye or Enclosure

Which Ridge Characteristic am I?

Delta

Which Ridge Characteristic am I?

Double Bifurcation

Which Ridge Characteristic Am I?

Trifurcation (Very Rare)

What is the approximate center of a ridge pattern called?

Core

Why do we leave fingerprints?

The skin ridges of the fingerprints are populated with sweat glands The skin ridges of the fingerprints are populated with sweat glands. Perspiration is discharged and deposited on the skin surface. A fingerprint is a deposit of 98% perspiration, 1% amino acids (proteins) and 1% oils that forms on the friction ridges of fingers, palms and feet and is left on a surface when contact is made.

What are the three categories for describing fingerprints at crime scenes?

Plastic Prints Latent Prints Patent Prints

What are Plastic Prints?

A plastic impression is a print that is readily visible with the naked eye due to the print detail being an impression in usually a soft surface. The most common types of surfaces or substances encountered at a crime scene are window putty, dust, dirt or mud.

What are patent prints?

A patent print impression is readily visible to the naked eye. It usually results by a finger touching a surface after it has been in contact with a colored material. The most common substances found at a crime scene are blood, paint, grease, and ink.

What are Latent Prints?

Latent print impressions are prints not readily visible to the naked eye. These impressions are caused by the transfer of body perspiration and oils to a particular surface. There are several techniques to make a latent print become visible, depending upon the type of surface, the manner in which the prints were left, and the quantity of material left behind.

What are the national statistics for fingerprint pattern types?

Loops: 60% Whorls: 35% Arches: 5%

What is the name of the fingerprint classification system that is used to classify prints according to how many whorls a person has?

The Henry Classification System

Which is the simplest type of fingerprint pattern?

Arch

Which fingerprint pattern must have at least two deltas by definition?

Whorls

Which fingerprint pattern has one or more ridges that enter and exit on the same side of the print?

Loops