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What is Dactyloscopy?
HINT: In the field of Dactylics, you collect dactylograms.
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__________ is the study of fingerprint identification.
Police investigators are experts in collecting “dactylograms”, otherwise known as fingerprints.
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3. Origin of fingerprint:
Look at your fingertip. Ridges cause for a better grip
Develop in the womb (week 17)
Unlike the rest of the body fingerprints______ ______
Increase in size, more prominent
When the finger touches a surface, perspiration and oils are transferred onto that surface, leaving a pattern called fingerprints.
What glands are found in our hands and toes?
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All fingers, toes, feet, and palms are covered in small ridges.
These ridges help us get or keep our grip on objects.
Natural secretions plus dirt on these surfaces leave behind an impression (a print) on those objects with which we come in contact.
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History
Fingerprints have been used for many purposes for at least 3000 yrs.
Chinese used to sign documents
St. Louis police first used fingerprinting for identifying
Who developed the idea of fingerprint identification?
Chinese used them as a signature on documents. St. Louis City Police were first in US to use fingerprinting for identification.
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Francis Galton
Galton-first person to study them and develop a system of classifying. In 1892, published Finger Prints.
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History Cont’d
In the 1920’s Federal prisons began to use them to identify prisoners
_____, Automated Fingerprint Identification System- FBI
“story” of William West
Do your prints change?
AFIS is the computerized system that compares fingerprints to the million of prints in the FBI database.
William West was arrested for burglary and sent to Leavenworth prison in Kansas. Upon his arrival he was put through the standard identification procedures –name, photograph, birth date and Bertillon measurements taken. When the authorities went to file is information based on his Bertillon Number, they found a prisoner already incarcerated that had that number. This prisoner had the name Will West and he looked like William West. BUT, their fingerprints were different. The story goes that this is when the federal prisons in the US changed to fingerprints. Cool story but not exactly true. Both men did exist, were in Leavenworth, looked alike, had similar names, the same Bertillon number but different prints. However, they were not in Leavenworth at the same time. With some research, it was determined years later that these two men were very distant cousins.
Prints do not change. That is, your prints do not become different with time. You can scar them but they do not grow back as different shapes.
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8. Speaking of changing prints…
John Dillinger
-paid Dr. $5000 to change his face and “remove” his fingerprints. Dr. put acid on his fingers
John Dillinger was the FBI’s most wanted man during his day. He was captured but escaped from a group of G-men by making a fake pistol out of wood. He then paid a Doctor $5000 to change his face and fingerprints. He received some minor facial changes and the Dr. put sulfuric acid on his fingertips causing them to have scarring on the fingerprints. Enough of his prints remained for them to be used to identify his bullet riddled body when he was later captured.
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9. More Attempts at Change
Roscoe Pitts
-hired a Dr. to literally remove his fingerprints. The Dr. grafted abdominal skin onto his fingers
Roscoe Pitts was a career burglar. He was, however, tired of serving time for being caught by the fingerprints he left at the scenes. He paid a Doctor to remove his prints. The Dr. skinned his fingers on the palm side of the hand and sewed them into his lower chest skin for skin that has no ridge characteristics to grow on this side of his fingers. When his fingers had sufficiently healed, Pitts began burglarizing again. He was so sure that he couldn’t be caught that he left palmprints at the scenes which lead to his arrest.
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One More Attempt..
Donald Roquierre
drug dealer in NJ
Paid Dr. to change his prints
Cut squares of skin from his prints and turn them upside down, then sewed them back in.
Donald Roquierre was a drug dealer in New Jersey who again paid a Doctor to change his prints. This Dr. cut squares of skin out of Roquierre’s prints turned them upside down and sewed them back in. Fingerprint experts could simply turn the original tenprint cards upside down to see the original section of the changed print as it was in the original card. Others have done even crazier things to change their prints. A man in Mexico had a Dr. exchange ridge skin from his feet with skin from his fingerprints. Others have had the prints scarred by using very sloppy sewing techniques to cause a deliberate heavy scarring on the print. How do we know of these cases??? They we all caught by the parts of their prints that remained around the scarring or a girlfriend or others turned them in!
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Various attempts
A man in Mexico had a Dr. exchange ridge skin from his feet with skin from his fingerprints.
Others have had the prints scarred by using very sloppy sewing techniques to cause a deliberate heavy scarring on the print.
How do we know of these cases??? They we all caught by the parts of their prints that remained around the scarring or a girlfriend or others turned them
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12. Identifying a Fingerprint
Categories
*Loops - ~65% of fingers have them
*Whorls- ~30% of fingers have them
*Arches- ~5 % of fingers have them
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Deltas
Can be used to determine if a print is a loop, whorl or arch
Sorority- Delta sign
Loops have _______
Whorls have two deltas
Arches have no deltas
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Loops
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15. Loops
Radius
Ulna
Left Hand
Radial- bottom of the loop points out toward the thumb-side of the hand
Ulnar- Bottom of the loop points out toward the little-finger-side of the hand
These patterns are named for their positions related to the radius and ulna bones, i.e. the bone the loop opening is facing towards.
L – Radial Loop
R - Ulnar Loop
L – Ulnar Loop
R - Radial Loop
Delta
X-Ray Imagine:

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Whorls
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17. Whorls
Whorls have at least one ridge that makes (or tends to make) a complete circuit. They also have at least two deltas. If a print has more than two deltas, it is most likely an accidental.

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Whorls Continued
Four types of whorls
Double Loop-has two loops, one upside down next to the other.
Find the deltas?
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19. Arches
Arches are the simplest type of fingerprints that are formed by ridges that enter on one side of the print and exit on the other. No deltas are present.
Tented Arches
Similar to the plain arch,
but has a spike in the center.
Spike or “tent”
Plain Arch
Ridges enter on one side and
exit on the other side.

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Which fingerprint pattern is the most common?
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LOOP!
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Which fingerprint pattern is the least common?
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ARCH!
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Their Uniqueness
Randomly grown while in the womb
Friction and pressure on the areas where ridges form affect their final outcome
All fingers, toes, feet, and palms are covered in small ridges.
These ridges help us get or keep our grip on objects.
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Forming Fingerprints
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26. Latent Prints
Latent - The skin has deposits of oil and perspiration that normally coat its surface.
When the hand touches the surface, some of the moisture is transferred from the hand to the object, leaving an impression of the friction ridge detail.
Invisible to the naked eye

27. Latent Prints On most surfaces latent prints are not readily visible.
The word latent is defined as not visible to the naked eye.
That does not mean that the latent print is actually invisible.
On most surfaces, the impression will be revealed through the use of available powder or oblique lighting.
The impression must be enhanced or developed to be collected and seen completely.

28. Patent Prints
Patent Prints – A patent prints occurs as the result of transferring a foreign material coating to the skin of the fingers.
Examples of the foreign material would be substances like paint, tar, grease, blood, or ink.

29. Patent Prints
The best example of a patent impression would be the ink standards or eliminations that we, as investigators collect from individuals.
After the ink is applied, it becomes foreign material coating the hands of the individual.
A card is used as a transfer medium, thus becoming the object touched and the transference of the patent impression takes place.

30. Patent Print The word patent means obvious or evident.
Patent prints are visible and usually need no enhancement.
They are simply photographed and the item that they are deposited on is collected if necessary.
The photograph or object actually becomes the investigator’s lift.

31. Plastic or Molded Prints
A plastic or molded impression is deposited when the hands, fingers, or feet are pressed into a soft, rubbery type material that will retain the impression of the ridge detail.

32. Plastic or Molded Prints
The difference between a latent and a plastic or molded print - Where a latent print is deposited on the surface, a plastic or molded impression would be deposited into the surface.
Examples of the materials where a plastic or molded impression would be deposited are clay, wet paint, blood, or tar.

33. Plastic or Molded Prints
Plastic or molded impressions are visible and usually need no enhancement.
They are simply photographed and if necessary, the item is collected and may have the ability to be casted.

34. Methods to Enhance Latent Prints
Four common methods of latent print enhancement:
1) Lifting Powder Application
2) Iodine Fumigation
3) Cryanoacrylate Fumigation
4) Ninhydrin Technique
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35. Lifting Powder Application
Fingerprint powders are colored, fluorescent, or magnetic materials that are very finely ground and are brushed lightly over a suspected print to produce contrast to the background.
black, white and other colors, including metallic.
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Once the lifting powder has been successfully applied a fingerprint is then “lifted” using a wide piece of clear smooth tape.
This technique is best used on smooth solid surfaces, e.g. walls, glass, knife.
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37. Iodine Fumigation Technique
Iodine, a solid crystal, is heated and transformed into a vapor. This is known as sublimination.
The suspect material is put into an enclosed cabinet known as a fuming cabinet.

38. Iodine Fumigation Technique Cont.
Iodine is placed at the bottom of a glass chamber
Object with suspected latent print is suspended
1)Sealed, 2)reaction occurs, 3)color, 4) photographed
This technique is best used on light-colored light weight/low density objects, e.g. paper, fabrics
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39. Iodine Fuming
The iodine crystals are heated and the vapors fill the chamber and combine with the latent print to make it visible.
In order to have a permanent record of the latent prints, the prints must then be photographed immediately or fixed with a 1% solution of starch and water that is sprayed on; for they will fade once the fuming process is stopped.

40. Cryanoacrylate Fumigation
Cryanoacrylate is a very strong glue. It has tendency to stick to the body oil residue found in fingerprints.
Cryanoacrylate begins to reacts with oil and leaves a whitish-grey film which is visible to the human eye
Photograph **Work bests upon dark-colored dense objects, e.g. guns, knife handles
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41. Ninhydrin
The amino acids present in perspiration chemically react to ninhydrin forming a purple-blue color.
Ninhydrin is sprayed onto the porous surface containing the latent prints.
Within an hour or two the prints begin to appear.
Ninhydrin is often the preferred method because of it is extremely sensitive and easy to apply.

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Fingerprint search systems match prints by comparing the positions of bifurcations and ridge endings
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43. 7 Ridge Characteristics
Bifurcation- one ridge splits into two
Enclosure- ridge splits then comes back together
Ridge ending- ridge stops
Island or Dot – ridge that looks like the dot on an I
Ridge crossing- two ridges cross one another
Short Ridge- ridge that is longer than an island but not very long
Spurs- bifurcated ridges with on side only a few mm in length
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45. Ridge Characteristics
enclosure
Ridge Ending
island
Short Ridge
spur
Bifurcation
Ridge Crossing looks like
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46. How Latent Prints Are Discovered
Alternative Light Source
Chemicals
Powders

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Comparing Prints
To determine if a print from a scene is consistent with a control from a suspect
Look for points (Ridge Characteristics)
Have same ridge characteristics
Accepted standards are eight points for most agencies
FBI requires 12 points
A point is a location on the skin of a person that has a ridge characteristic; bifurcation, dot, ridge ending, etc. If a suspects print has eight points that are the same as the eight points on a print lifted from a crime scene, then a fingerprint expert can say that the lifted print is consistent with the print from the suspect.
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Control Prints
Collected on “tenprint” cards
By rolling each print in ink
Or scanned
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Collection of Prints
Dusted prints are lifted with 1 ½ -2 inch wide clear tape and placed onto a piece of cardstock
Labeled with a minimum of the collector’s name, date and time of lift, and location of the lift.
Chemically developed -photographed
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Storing Print Cards
Henry Number
Print type given a number
Number based on
Is it a type of whorl and
Which finger it is on.
Used to create a set of fractions….
RI + RR + LT + LM + LL + 1 =
RT RM RL LI LR 1
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Henry Number
Fingers are given points if they have a type of whorl (plain, double loop, central pocket or accidental)
How many points depends on the finger
If they are on right thumb or right index they get 16 points
Right middle and ring get 8
Right little and left thumb get 4
Left index and middle get 2 and
Left ring and little get 1
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An Example
If you have a set of prints with the following types of fingers:
RT- double loop, RI-ulnar loop, RM-ulnar loop, RR-plain whorl, RL-radial loop.
LT-plain whorl, LI-ulnar loop, LM-double loop, LR-plain whorl, LL-ulnar loop
Only the RT, RR, LT, LM &LR have types of loops so they get points. All others are zero.
You get the following number:
= don’t forget to add …
1/1 at the end!! To give 15/18 as the Henry Number
RT= right thumb, RI= right index finger, RM= right middle finger, RR= right ring finger, RL= right little finger
LT= left thumb, LI= left index, LM= left middle, LR= left ring, LL= left little
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Try It!
Are these whorls? Set up the fractions on your paper.
How many points does each get?
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Fingers 6, 7 and 8
Are these whorls?
How many points do they get?
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How many points do they get?
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To Get the Number
Put them together to make a set of fractions
RI + RR + LT + LM + LL + 1 =
RT RM RL LI LR 1
Sum the top number and put it over the sum of the bottom number
= 5
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Not Real Math
Police math!
DO NOT simplify
All prints with same number are stored in same section of files.
Who has 1/1??
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58. Three ways you can leave a print
Invisible (latent) print
Leave the sweat and oils from skin on a surface
Visible print
Touch a colored liquid, then leave it on a surface
Plastic print
Touch a soft surface that will mold to your ridge characteristics
Examples of visible prints: ones left from wet paint, colored oils (brake fluid, transmission fluid, etc.) on fingers.
Examples of plastic prints: prints left in paint that is almost dry, soft cheeses like brie, milk chocolate bars, and caulk that is not dry.
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Latent Prints
Made up of
Fatty acids & Oils, picked up from areas of the skin that contain hair
Amino acids and proteins, also from areas of skin that contain hair
Salts, from sweat NaCl and KCl
H2O, from sweat
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60. Visualizing Latent Prints
Many ways
Most common is fingerprint powder and a brush
Magnetic brush and powder
Chemically develop the print
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61. Chemical Development of prints
Ninhydrin-reacts w/ amino acids to produce a complex “Ruhemann’s Purple”, a purple stain in the shape of the print
Iodine-believed to react w/ oils, forms a brownish yellow stain in shape of print
Silver Nitrate-reacts with NaCl to form AgCl, a brownish –grey stain in shape of print that evaporates in minutes.
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62. Other Chemical Development
Prints on Tape
Gentian Violet- used on sticky side of tape. Stains the skin cells left in the shape of the print and reacts with oils
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63. Chemical Development Cont’d
Superglue fuming w/ wand
Super Glue®- cyanoacrylate ester, in the gas form it may be attaching itself to the water molecules, forming a polymer over the print (catalyzed by Aluminum)
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