FINGERPRINTING ANALYSIS Prehistoric Fingerprinting Ancient Babylonians Fingerprints were

FINGERPRINTING ANALYSIS

Prehistoric Fingerprinting • Ancient Babylonians – Fingerprints were used on clay tablets for business transactions • Ancient China – Thumbprints found in clay seals

History of Fingerprinting • 1858 – Sir William Herschel – An English Chief Magistrate in India – Had people record their fingerprints when signing business documents

History of Fingerprinting • 1880 - Henry Faulds – Noticed fingerprints on prehistoric pottery – Published an article in “Nature” saying fingerprints could be used for identification – Wrote to his cousin, Charles Darwin, asking for help with developing a classification system – Darwin forwarded the letter to his cousin, Sir Francis Galton

History of Fingerprints • 1880 Henry Faulds – Suggested possibility of using fingerprints left at crime scene X 1882 Gilbert Thompson –First use of fingerprints in U. S Henry Faulds (1843 -1930)

History of Fingerprinting • 1883 – Alphonse Bertillon 1 st systematic attempt at personal identification Anthropometry • Body height • Length of middle finger • Length of left foot • Length of outstretched reach of both arms • Width of head • Length of head

History of Fingerprinting • 1892 – Sir Francis Galton – Published textbook Finger Prints • Outlined a fingerprint identification system • Suggested methods for recording fingerprints • Assigned three pattern types – Loops, Whorls, Arches • Demonstrated two fundamental principles underlying fingerprint identification system – Uniqueness – Permanence

History of Fingerprints • Uniqueness – Galton calculated that there was a possible existence of 64 billion different fingerprints – No two fingerprints have yet been found that are identical – Even identical twins have different fingerprints • Permanence – A fingerprint remains unchanged during an individual’s lifetime

History of Fingerprinting • 1891 – Juan Vucetich – Developed a searchable filing system for fingerprints – Used in most Spanish-speaking countries – Made one of 1 st criminal fingerprint identifications • 1897 – Sir Edward Richard Henry – Developed another searchable filing system – Adopted by Scotland Yard, in England.

History of Fingerprinting In 1903, Will West thought he was fooling the system at Leavenworth Penitentiary by stating that he was not already in the system at the Penitentiary for a previous crime. The clerk decided to look up his Bertillon number anyway. What was found was another man serving a life sentence for murder, already imprisoned in the Penitentiary, named William West This flaw in the system would have never been noticed, had Will West not lied when entering the Penitentiary for a second time in 1903 Will West William West

History of Fingerprinting • 1904 – World’s Fair – US police officers received training from Scotland Yard representatives • 1924 – FBI identification records – Federal Bureau of Investigations and Leavenworth Penitentiary merged and moved to Washington D. C.

What are Fingerprints? • Friction skin ridges found on the palm side of the fingers and thumbs • Also found on palms, toes, and soles of feet • Designed for firmer grasp and to prevent slippage

What are Fingerprints? • Human skin is composed of layers – Epidermis = outer skin – Dermis = inner skin – Dermal papillae = separates two layers • Determines pattern of ridges on skin’s surface • Develop in fetus and enlarge during growth

Dermal papillae separating the two layers of dermis

Ridge Characteristics • Minutiae – Details in a fingerprint – Identity, number, and location imparts individuality to a fingerprint – Used to make a point by point comparison by expert fingerprint examiners

Three Fundamental Principles of Fingerprinting 1. A fingerprint is an individual characteristic because no two fingers have yet been found to possess identical ridge characteristics (minutiae); 2. A fingerprint will remain unchanged during an individual’s lifetime; and 3. Fingerprints have general ridge characteristics that permit them to be systematically classified.

Ridge Characteristics

Ridge Characteristics • A fingerprint may contain up to 150 individual ridge characteristics • Crime scene prints usually have only a small number of ridges that are actually recoverable • To make a match an examiner has to determine that two prints have the same ridge characteristics in the same location to one another • Around 8 -16 points of similarity are needed to determine a match

Comparison 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. Kendall/Hunt Publishing Company 22

2 nd Principle: A fingerprint will remain unchanged during an individual’s lifetime A positive identification of John Dillinger from his fingerprints, even though he had mutilated them

Ridge Patterns • Three classes – Loops • 60 -65% of all fingerprints – Whorls • 30 -35% of all fingerprints – Arches • 5% of all fingerprints

3 rd 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, arches and whorls (LAW).

Loops • One or more ridges enters from one side of the print, re-curves, and exits from the same side – Ulnar loop: opens toward the little finger – Radial loop: opens toward the thumb Right Hand Ulnar Loop Right Hand Radial Loop

Loops • All loops must have ONE delta/triradius surrounded by type lines and a core Core Type lines Delta

Ulnar vs. Radial Loop

Whorls • Ridges are generally circular • All whorl patterns have type lines and AT LEAST TWO deltas

Whorls • 4 distinct groups – Plain whorl • At least 1 ridge makes a complete circuit • Imaginary line between deltas touches spiral ridge – Central pocket loop whorl • At least 1 ridge makes a complete circuit • Imaginary line between deltas does not touch spiral ridge – Double loop whorl • Made of 2 loops combined together – Accidental whorl • Contains 2 or more patterns or doesn’t fit anywhere else

Arches • Ridge enters from one side of the print, rises in the center and exits on the other side • DO NOT have – Type lines – Deltas – Cores

Arches • 2 Distinct groups – Plain arch • Ridges rise in the center in a wave-like pattern – Tented arch • Ridges rise in the center with a sharp spike

Primary Classification The Henry-FBI Classification System Each finger is given a point value. right left Kendall/Hunt Publishing Company 33

Primary Classification, continued Assign the number of points for each finger that has a whorl and substitute into the equation: right index right ring left thumb left middle left little +1 = right thumb right middle right little left index left ring +1 That number is your primary classification number. Kendall/Hunt Publishing Company 34

FBI System of Classification • Modification of the Henry system • Pair up fingers R. Index R. Thumb R. Ring L. Thumb R. Middle R. Little L. Middle L. Index L. Little L. Ring • Based on presence or absence or whorl pattern – – – 1 st pair: 16 points 2 nd pair: 8 points 3 rd pair: 4 points 4 th pair: 2 points 5 th pair: 1 point

FBI System of Classification • • Total the values Add 1 to the numerator and denominator Fraction is what you use to classify the prints Provides examiner with list of candidates in system to look at more closely • Can help narrow down suspect list • Final identification of an individual is based on comparison of minutia by examiner • Only useful when a full set of prints are available

Automated Fingerprint Identification Systems (AFIS) • Prints are scanned and encoded by computers • Digitally stores position and orientation of minutia for each print • Produces a list of file prints with the closest correlation to a question print for the examiner to compare • Still manually search known suspects in each case

Methods of Detecting Fingerprints • 3 kinds of crime scene prints – Latent – Visible – Plastic

Latent Prints • Each skin ridge contains a single row of pores – openings for ducts of sweat glands – Tops of fingerprint ridges get covered with sweat and oil – When a finger touches an item, sweat and oil are deposited onto the surface – This leaves an impression of the finger’s ridge pattern (fingerprint) – Invisible to the eye

Visible and Plastic Prints • Visible prints – Made by fingers coated in a colored material such s blood, paint, grease, or ink touching a surface • Plastic prints – Made when a finger leaves an impression in a soft material such as putty, wax, or dust

Methods of Detecting Fingerprints • Method used depends on surface type print is located on – Hard nonabsorbent surfaces • Examples: glass, mirror, tile • Powder or Super Glue treatment – Soft and porous surfaces • Examples: Paper, cardboard, cloth • Chemical treatment – – Iodine Fuming Ninhydrin Physical Developer Super Glue treatment

Methods of Detecting Fingerprints • Powders – Adheres to perspiration residues and body oil deposits – Applied with camel hair or fiberglass brush – Select color powder with best contrast – Magnetic Sensitive Powders • No bristles means less chance of destroying print • Useful on leather and rough plastics – Fluorescent Powders • Fluoresce under UV light • Useful on confusing or multi-colored backgrounds

Methods of Detecting Fingerprints • Iodine Fuming – Solid crystal of iodine is sublimated with heat • Sublimation = physical change from the solid directly to the gaseous state – Suspect material is placed in an enclosed chamber filled with iodine vapors – Iodine vapors react with fatty oils in print to form a brown deposit – Not permanent • Photograph developed print • Fix developed print with 1% starch solution

Methods of Detecting Fingerprints • Ninhydrin – Ninhydrin powder is mixed with acetone or ethanol to form a spray – Reacts with amino acids present in perspiration to form a purple deposit known as Ruhemann’s purple – Prints can develop within 1 -2 hours but can take up to 10 days – Development of prints is sped up if heated – Very sensitive • Used to get prints off paper as old as 15 years

Methods of Detecting Fingerprints • Physical Developer – Silver-nitrate based liquid reagent – ONLY method that is useful in developing prints on items that were once wet – Reacts with sodium chloride in fingerprint residue to produces a dark grey deposit – Destroys proteins so used last after all other chemical tests

Methods of Detecting Fingerprints • Super Glue Fuming – Heating superglue forms cyanoacrylate ester fumes – Suspect material is placed in an enclosed chamber filled with cyanoacrylate fumes – Fumes react with fats in fingerprint residue producing a hard, white deposit – Developed prints may be dusted with powders

Methods of Detection Review Powders What Reacts Perspiration With and oil Surface Notes Nonporous Iodine Ninhydrine Physical Developer Super Glue Fats Amino Acids Sodium Chloride Fats Porous and Nonporous Very sensitive Use Last OR Use if item was wet Porous Not permanent

Preservation of Developed Prints • Prints must be permanently preserved for: – future comparison – possible use in court as evidence • Steps to preservation – Photograph prints – Small objects: cover with cellophane – Large objects: lift prints with tape and secure to cardboard backing