Forensics- Fingerprints

- A type of minutiae that looks like a short dash in an enclosure or circle. - Longer than a dot but shorter...missed the rest

Short ridge/Island

- A type of minutiae that looks like a curved thorn or a hook. - A ridge that bifurcates and one of the lines of the bifurcation ends quickly

Spur

The papillae form a boundary that determines the friction ridge structure of the epidermis.

The Anatomy of Fingerprint- Dermal papillae

Skin is made up of an outer epidermal layer separated from the inner dermal layer by the papillae.

The Anatomy of Fingerprint- Layers of skin

Every person has a different, unique, and individual fingerprint. They are a way to identify one person from another.

The Anatomy of Fingerprint- Purpose

Loop - Radial loop - Ulnar loop Whorls - Plain whorl - Accidental whorl - Central pocket loop whorl - Double loop whorl Arches - Plain - Tented

Three major fingerprints and their respective subclasses

- When there are 3 branches. Looks like a three pronged fork. - One ridge splits into three - Can be "upward" or "downward"

Trifurcation

Loops

What is the most common type of fingerprint pattern?

Types of crime-scene fingerprints

- Visible - Plastic (patent) - Latent

- In 1881, Bertillon was employed as a ledger clerk at the police headquarters in Paris. He suggested using certain body measurements as discriminating characteristics to identify habitual offenders. - Bertillon first recommended recording 11 measurements, such as height, reach, width of head, length of foot, and so on. - Over the years, a very consistent method of measurement, description, and classification was worked out, and by the end of the 19th century it was accepted almost everywhere. - The science of human measurements is called anthropometry.

Alphonse Bertillon

- Least common and simplest fingerprint pattern (5%). Arches have no delta or core. All friction ridges enter one side and exit the other while rising upward in the middle. - Can be confused with loops by inexperienced observers. - They are divided into two groups, plain and tented arches. - No delta

Arches

- common minutiae, shaped like a two pronged fork. They are easy to see and there are many of them. - One ridge splits into two - Can be "upward" or "downward"

Bifurcation

- Connects one ridge to another. Sometimes it looks like an S shape. - A ridge that connects one ridge with another - Not to be confused with a ridge crossing

Bridge

During China's T'ang dynasty (eighth century AD), clerks used inked fingerprints on business contracts; this practice was not so different from using a chop mark.

Chinese

The study of fingerprints.

Dactyloscopy

- a triangular area found in all loops and whorl patterns. It is usually shaped like the silt formation near the mouth of a river flowing into the sea. - Looks like a "T" in the road - Always found in loops (1) and Whorls (2)

Delta

- A type of minutiae that looks like a spot. - Also known as an island - Small circular ridge

Dot

- The point in a fingerprint where a ridge divides to form two ridges. - A bifurcation that comes right after a bifurcation

Double bifurcation

- A type of minutiae that looks like an eye with nothing inside. - A ridge that splits into two and the becomes one ridge again

Enclosure/Eye

- A British anthropologist who studied both dactyloscopy and Bertillon's anthropometry. - In 1891 and 1892, he published two books in which he showed how to classify fingerprints using loops, whorls, and arches, as well as a secondary, more complex method. - Most important, however, he showed that a person's fingerprints stay the same from birth until death, that no two fingerprints are identical, that prints cannot be altered, and that it is possible to classify a very large number of prints. - By 1897, working with Galton, Edward Richard Henry, inspector general of police in Bengal, India, had simplified Galton's classification system and established the Henry classification system of identification in India, replacing Bertillon's method. - Scotland Yard adopted Henry's system in 1901. Today, most English-speaking countries use some form of the Henry system.

Francis Galton

- A health missionary in Tokyo, Japan, who was interested in molded fingerprints in old pottery. - He published a scientific paper in 1880 about the possibility of using fingerprints to identify criminals. - Believed that fingerprints were unique. - Claimed that fingerprints did not change over a lifetime and that they could be classified for sorting purposes to help in identification. - Described an ink-and-transfer method of recording prints. - Was the first to use fingerprints to solve a crime.

Henry Faulds

5

Identify the feature in this fingerprint that is known as a delta.

6

Identify the feature in this fingerprint that is known as a ridge dot.

1

Identify the feature in this fingerprint that is known as a ridge ending.

3

Identify the feature in this fingerprint that is known as a short ridge.

2

Identify the feature in this fingerprint that is known as an enclosure.

4

Identify the feature in this fingerprint that is known as bifurcation.

Radial loop

Identify which type of loop is represented in this fingerprint from the right hand.

Ulnar loop

Identify​ which type of loop is represented in this fingerprint from the right hand.

- The loop pattern has one or more ridges entering from one side, curving, then going out from the same side it entered from. If even one ridge exits the same side, it is a loop. - There are two subgroups to the loop: The radial loop and an ulnar loop. Without knowing which hand made the print, you cannot tell if the loop is radial or ulnar.

Loops

Radial loop: opens toward the thumb, that is, toward the radius, the shorter of the two bones in the forearm.

Loops- Radial Loop

Ulnar loop: opens toward the little finger, that is, toward the ulna, the minor bone of the forearm. Ulnar loops are more common.

Loops- Ulnar Loop

- AKA minutiae (in description of fingerprints, ridge characteristics). - The fine structure of ridge characteristics can be used to individualize a fingerprint. -How each individual ridge appears in a fingerprint -Gives fingerprints their individuality -There must be a match of 10-14 ridge characteristics for a fingerprint to be matched

Ridge characteristics- Definition

- A short ridge that runs between two parallel ridges. - When two separate ridges bisect/cross each other

Ridge crossing

- The point where a ridge ends abruptly. - A ridge that stops

Ridge ending

- Fingerprint pattern with at least two deltas and a core. - Approximately 20 percent of fingerprints have plain whorls. - Composites (a mixture of two or more basic patterns) and accidentals (prints too irregular to fall into any other group) make up about 10 percent of all fingerprints. - Two deltas. On the bottom right and left of the whorl - Plain whorl - Accidental whorl - Central pocket loop whorl - Double loop whorl

Whorls

- A highly placed British civil servant who decided to require Indians to add their fingerprint to contracts. - Later, in 1877, he introduced the use of fingerprints as a means of identifying prisoners. - Believed that fingerprints were unique.

William Herschel