Fingerprints

Cyanoacrylate for developing latent prints

"Superglue" fumes react with water and other fingerprint constituents to form a hard, whitish deposit.

Plastic print

(aka indented or molded print) Three dimensional print made as indentations in soft material such as fresh paint, putty, wax, soap, gum, candy bar that was softened Teeth—bite marks are unique and can be used to identify suspects. These imprints were placed in gum and could be matched to crime scene evidence.

Plain and central pocket whorls

Both have at least one ridge that makes a complete circuit.

What are the five types of lip prints?

Branching grooves, diamond grooves, short vertical grooves, long vertical grooves, and rectangular grooves.

How can fingerprint patterns be changed?

By cutting through the skin in a systematic way to alter the pattern, it takes a month to heal.

Accidental whorl

A pattern not covered by other categories.

Powders for developing latent prints

Adhere to both water and fatty deposits. Choose a color to contrast with the background.

How does the primary classification system work?

Assign the number of points to each finger that has a whorl and substitute into the equation: Right index Right ring Left thumb Left middle Left pinky +1 = Right thumb Right middle Right pinky Left index Left ring +1 = That number is your primary classification number.

Footprints

are taken at birth as a means of identification of infants.

Ear prints

catches murderer... A man has been convicted of suffocating an eldery woman on the basis of earprint evidence. The assailant was caught after police matched the inprint of his ear on the victim's window. Police believe that the thief put his ear to the window to listen for signs of anyone home.

Palm prints

friction ridges can be identified and may be used against suspects

Blood vessel patterns

the eye may be unique to individuals. They are used today for various security purposes.

Minutiae

Characteristics of ridge patters

What are fingerprints composed of, and how. Are they deposited?

Fingerprints are composed of 1/2 salt and 1/2 complex organic compound such as amino acids, lipids, vitamins, and perhaps additional body oils picked up on the finger from touching oily parts of the body or hair on parts of the body.

What is meant by a latent print, and how can one be developed?

Fingerprints made by the deposit of perspiration or body oils; invisible to the naked eye until developed.

All fingerprints have class evidence such as loops, whorls, arches, cores, deltas, bifurcations, ridges, Spurs, and the like. Why, then, are fingerprints considered individual evidence rather than class evidence?

Fingerprints stay the same from birth until death, no two are identical, they can't be altered, all making it possibly to classify a very large amount of prints.

Iodine for developing latent prints

Fumes react with oils and fats to produce a temporary yellow-brown color.

Arch

Has friction ridges that enter on one side of the finger and cross to the other side while rising upward in the middle, do NOT have type lines, deltas, or cores, they are the LEAST common and the simplest, and there are two different types.

What are some other types of prints?

Lips—there are several common patterns Voice—electronic pulses measured on a spectrograph Foot—size of foot and toes; friction ridges on the foot Shoes—can be compared and identified by type of shoe, brand, size, year of purchase, and wear pattern Palm prints Footprints Ear prints

Double loop whorl

Made of two loops

Loop

Must have one or more ridges entering and exiting from the same side, must have one delta, they make up about 65% of fingerprints, and there are two different types.

What would be the best way to visualize latent fingerprints on a matchbox?

Ninhydrin

AFIS

The Automated Fingerprint Identification System—a computer system for storing and retrieving fingerprints Established in the 1970s, this enables law enforcement officials to: Search large files for a set of prints taken from an individual Compare a single print, usually a latent print developed from a crime scene By the 1990s, most large jurisdictions had their own system in place. The problem: A person's fingerprints may be in one AFIS database but not in others.

Primary classification of fingerprints

The Henry-FBI Classification system

Whorl

They have at least two deltas

How to classify ridge characteristics...

Through minutiae

What type of fingerprint would be likely to be found in, on, or by means of chalk?

Visibke

What type of fingerprint would be likely to be found in, on, or by means of blood?

Visible

What type of fingerprint would be likely to be found in, on, or by means of dust?

Visible

What type of fingerprint would be likely to be found in, on, or by means of wood tabketop?

Latent

Ridge characteristics

Ridge ending Island or short ridge Bridge Eye or enclosure Delta Bifurcation or fork Dot Spur Double bifurcation Trifurcation

The Henry-FBI Classification system

Each finger is given a point value. Right pinky-4 Right ring finger-8 Right middle finger-8 Right pointer finger-16 Right thumb- 16 Left thumb-4 Left pointer finger-2 Left middle finger-2 Left ring finger-1 Left pinky-1

What would be the best way to visualize latent fingerprints on a cigarette butt?

Iodine

What would be the best way to visualize latent fingerprints on a hanker chief?

Iodine

What are the fundamental characteristics of finger prints?

It is an individual characteristic, it remains unchanged during an individual's lifetime, they have general characterist ridge patterns that permit them to be systematically classified, and the Henry system is used.

What type of fingerprint would be likely to be found in, on, or by means of a gun barrel?

Latent

What type of fingerprint would be likely to be found in, on, or by means of leather jacket?

Latent

What type of fingerprint would be likely to be found in, on, or by means of newspaper?

Latent

What type of fingerprint would be likely to be found in, on, or by means of polyethylene bag?

Latent

What type of fingerprint would be likely to be found in, on, or by means of skin?

Latent

What type of fingerprint would be likely to be found in, on, or by means of windowpane?

Latent

Ulnar loop

Opens towards the "pinky" (little finger)

Radial loop

Opens towards the thumb

What are the two types of arches?

Plain and tented

What type of fingerprint would be likely to be found in, on, or by means of Romano cheese?

Plastic

What type of fingerprint would be likely to be found in, on, or by means of fudge?

Plastic

What type of fingerprint would be likely to be found in, on, or by means of mud?

Plastic

What type of fingerprint would be likely to be found in, on, or by means of snow?

Plastic

What would be the best way to visualize latent fingerprints on vinyl upholstery?

Powders

What are the two different types of loop fingerprints?

Radial and ulnar

Ninhydrin for developing latent prints

Reacts with amino acids to produce a purple color.

Silver nitrate for developing latent prints

Reacts with chloride to form silver chloride, a material that turns grey when exposed to light.

Developing latent prints

Requires substances that interact with secretions, causing the print to stand out against its background. Such as powders, iodine, ninhydrin, silver nitrate, and cyanoacrylate.

What would be the best way to visualize latent fingerprints on a broken bottle?

Superglue

What would be the best way to visualize latent fingerprints on a light bulb?

Superglue

What would be the best way to visualize latent fingerprints on a toilet seat?

Superglue

What is the difference between a fingerprint pattern and a ridge characteristic?

The individuality of any fingerprint is based not upon the general shape or pattern that it forms, but instead upon its ridge structure and specific characteristics (aka minutia)

How many types of whorl fingerprints are there and what are they? Describe each type.

There are four types. Plain whorls make up approximately 20%, there is central pocket whorls, double loop whorls which make up approximately 10%, and there are accidental whorls.

Comparing fingerprints

There are no legal requirements in the United States on the number of points required for a match. Generally, criminal courts will accept 8 to 12 points of similarity.

IAFIS

the FBI's Integrated Automated Fingerprint Identification System, which is a national database of all 10-print cards from all over the country