Fingerprints

1. Fingerprints “Fingerprints cannot lie, but liars can make fingerprints” -Unknown

2. What is a fingerprint? • A fingerprint is an impression of the pattern of the ridges on the last joint of a person’s finger. • Dactyloscopy  The study of fingerprints

3. The History of Fingerprints • Chinese used fingerprints to sign legal documents as far back as threethousand years ago. • William Herschel, an English civil servant in India, required natives to sign contracts with an imprint of their right hand. • In 1880, Scottish physician, Henry Fauld wrote that skin ridge patterns could be important in identification work of humans. - Fauld offered to set up a system of fingerprints at Scotland Yard (at his own expense). - Rejected in favor of the Bertillon System.

4. Alphonse Bertillon • The first systematic attempt at personal identification was devised and introduced by the French police expert, Alphonse Bertillon, in 1883. • Bertillon’s System  Relied on: 1. Portraite Parlé – Detailed description of the individual. 2. Full length and profile photographs. 3. Anthropometry – A system of precise body measurements.

5. Anthropometry • A method of identification. • Based upon the premise that the dimensions of the human skeletal system remained fixed from age 20 until death. • Eleven (11) measurements taken • to include height, width of head and length of left foot.

6. Problem with Bertillon’s System • In 1903, William West was in jail. When they tried to put Will West in prison he was apparently already there….? • Bertillon’s method failed due to the fact that both men had almost exact anthropometric measurements. William West Will West

7. Francis Galton • In 1892, published the classic work Finger Prints. • In this book he discussed the anatomy of fingerprints and suggested methods for recording them. • Proposed three pattern types: loops, whorls and arches. • No two prints are identical. • An individual’s prints remain unchanged from one year to the next.

8. Sir Edward Henry • In 1897, Henry, applied Galton’s identification system for fingerprints while he was inspector general of police work in Bengal, India. • Henry eventually simplified and modified Galton’s work and created his own fingerprint identification system. • Henry’s fingerprint classification system was adopted by Scotland yard in 1901, and is still used in some form by most English-speaking countries in the world.

9. History of Fingerprints in the US 1901 – The first systematic use of fingerprints was adopted by the New York Civil Service Commission. 1904 – American police received training in fingerprint techniques from Scotland Yard representatives. 1924 – Fingerprint records from the Bureau of Investigation and Leavenworth merged to form records for the newly formed FBI.

10. Admissibility of Fingerprint Evidence • Challenged in the case of United States v. Byron C. Mitchell. • The defendant’s lawyer argued that under Daubert guidelines fingerprints were not unique. • Judge upheld admissibility and ruled: 1. Human friction ridges are unique and permanent. 2. Human friction ridge skin arrangements are unique and permanent.

11. Anatomy of Fingerprints • Fingerprints are also known as “friction skin ridges.” • Gives us a firmer grasp with less slippage. • Skin ridges enlarge during growth but do not change. • Consists of hills (ridges) and valleys (grooves). • Ridges and grooves make the lines we see, known as fingerprints.

12. Skin Layers • Epidermis is the outer layer of skin. • Dermis is the inner layer of skin. • Dermal Papillae is the in between layer of skin.

13. Papillae • A boundary of cells separating the epidermis and the dermis. • Determines the form and pattern of the ridges on the surface of the skin. • Development occurs in the fetus and remains unchanged throughout life. • Each human has a different papillae structure, so no two humans will have the exact same fingerprints. - Identical twins even have different fingerprints form each other.

14. Pores • Opening of sweat ducts. • Perspiration is discharged through the pores and transferred to surfaces and leaves an invisible impression, called a latent fingerprint. • Fingerprints initially may weigh 1/10,000 of a gram. • After the evaporation of the water from the sweat, the fingerprint is made up of residue that may consist of salt, amino acids, lipids, vitamins, and oils.

15. Attempts to Obliterate Fingerprints • John Dillinger tried to destroy his prints with acid - didn’t work. • Roscoe Pitts had his fingerprints surgically removed and skin from his rib cage grafted onto fingers – didn’t work. • Damage to dermal papillae = a scar. • Scar = a new way to ID.

16. Other Types of Prints • Ears - shape, length and width. • 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. • Tongue

17. Palm Prints Palm – Friction ridges can be identified and may be used against suspects.

18. Foot Prints Footprints are taken at birth as a means of identification of infants.

19. Lip Prints Lips - Display several common patterns • Short vertical lines • Short horizontal lines • Crosshatching • Branching grooves

20. Bite Marks • 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.

21. Eye Prints • The blood vessel patterns in the eye may be unique to individuals. They are used today for various security purposes.

22. Fundamentals of Fingerprints • First Principle • A fingerprint is an individual characteristic. • No two fingerprints have been yet to be found with the same identical ridge characteristics (minutiae). • Minutiae are individual characteristic ridge patterns. • Ridge ending • Short ridge • Dot or fragment • Bifurcation • Double bifurcation • Trifurcation • Bridge • Island • Enclosure • Spur

25. Ridge Characteristics • Complete fingerprints may contain as many as 150 individual ridge characteristics. • Usually fingerprints from crime scenes are partials and only a small number of ridges are actually recovered from the scene. • If two prints are said to be the same, they will have to reveal characteristics that not only are identical, but have the same relative location to one another. • When comparing prints, eight to sixteen identical ridge characteristics are usually needed to say that a match has occurred. • The fingerprint expert uses his or her judgment to determine whether or not two ridges match. • No statistical studies have been done to determine how many ridge comparisons are necessary.

26. Second Principle - A fingerprint will remain unchanged during an individual’s lifetime.

27. Third Principle - Fingerprints have general ridge patterns that allow them to be systematically classified. - The three general patterns are loops, arches, and whorls (LAW).

28. Loops • A loop pattern is defined as having one or more ridges entering from one side, curving, and then going out form the side it entered. • They are the most common pattern on fingers. • Types: • Radial - opens toward the thumb. • Ulnar - opens toward the “pinky” (little finger). • Which type of loop is this, if it is on the right hand? Left hand?

29. All loop patterns show a delta. - A triangular ridge pattern. • All loop patterns also have a core near the center of the pattern. • Type lines are diverging ridges surrounding the pattern.

30. Whorls • All whorls have at least two deltas and a core. • Whorls have lots of circles that do not leave either side of the print. • Types • Plain • Central Pocket • Double Loop • Accidental

31. These whorls have at least one ridge that makes a complete circuit. • The ridge may be in the form of a spiral, oval, or variant of a circle.

32. Double loop – When two loops are combined into one fingerprint. • Accidental – When two or more loops are combined into one fingerprint.

33. Arches • Arches are the least common and the simplest of the fingerprint patterns. • The friction ridges enter from one side of the finger and exit from the other while rising up in the middle. • Arches do not have deltas, type lines, or cores.

34. There are two types of arch fingerprint patterns. • Plain – Wavelike arches with low peaks. • Tented – Spiked arches with high peaks.

35. Types of Fingerprints • Visible Prints • Formed by contact with colored material such as blood, paint, grease, or ink. • Plastic Prints • Ridge impressions left on a soft material such as putty, wax, soap, or dust. • Latent Prints • Caused by body transfer of oils present on finger ridges. • Latent fingerprints are those that are not visible to the naked eye. • Most secretions come from three glands: • Eccrine - largely water with both inorganic (ammonia, chlorides, metal ions, phosphates) and organic compounds (amino acids, lactic acids, urea, sugars). Most important for fingerprints. • Apocrine - secrete pheromones and other organic materials. • Sebaceous - secrete fatty or greasy substances.

36. Methods of Detecting Latent Prints • Method of detection depends on the surface in which the print is left. • Hard Surface - Use powder method or super-glue. • Use black powder on white surfaces and white powder on dark surfaces. • Use fluorescent powder on multi-colored surfaces and use magnetic powder on leather or rough plastic. • Soft or Porous Surfaces - Use chemical methods. • Whatever the method, the medium ends up adhering to the perspiration, compounds, and oil found within the fingerprint. • It may be necessary to attempt more than one technique, done in a particular order so as not to destroy the print.

37. Chemical Procedures to Detect Latent Prints • Iodine – • Fumes react with oils and fats to produce a temporary yellow brown reaction.

38. Ninhydrin – - Reacts with amino acids to produce a purple color.

39. Silver Nitrate – - Reacts with chloride to form silver chloride, a material that turns gray when exposed to light.

40. Cyanoacrylate – - “Super glue” fumes react with water and other fingerprint constituents to form a hard, whitish deposit.

41. AFIS • The Automated Fingerprint Identification System - A computer system used for storing and retrieving fingerprints. • Began in the early 1970’s 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 1990’s most large jurisdictions had their own system in place. - The problem was that a person’s fingerprints may be in one AFIS but not in others. • IAFIS - The FBI’s Integrated Automated Fingerprint Identification system which is a national database of all 10-print cards from all over the country. - It also includes criminal history, mug shots, photos of scars or tattoos, height, weight, hair and eye color, and aliases.