1. FORENSIC SCIENCE Prints
GOAL:
Produce a print portfolio that explains print information and demonstrates your best work in lifting and identifying a variety of prints.

2. BERTILLON SYSTEM

3. Prints Making Prints Lifting Prints Other Types of Prints
Rolling prints
Modus Operandi--primary identification number
Lifting Prints
Black, white and fluorescent powder
Chemicals--ninhydrin, iodine, silver nitrate, cyanoacrylate
Other Types of Prints
Palm, lip, teeth, eye, ear, voice, shoe and feet prints

4. Fundamental Principles of Fingerprints
A fingerprint is an individual characteristic.
A fingerprint will remain unchanged during an individual’s lifetime.
Fingerprints have general characteristics ridge patterns that permit them to be systematically classified.

5. Ridge Characteristics
Minutia--lines of the fingerprint
ridge ending
bifurcation
short ridge
dot or fragment
island
enclosure

6. MINUTIA
RIDGE ENDING
BIFURCATION

7. MINUTIA
SHORT RIDGE
DOT or FRAGMENT
ISLAND
ENCLOSURE

8. Arch
An arch has friction ridges that enter on one side of the finger and cross to the other side while rising upward in the middle. They do NOT have type lines, deltas, or cores.
Types
Plain
Tented

9. Loop
A loop must have one or more ridges entering and exiting from the same side it began. Loops must have one delta.
Types
Radial--opens toward the thumb
Ulnar--opens toward the “pinky” (little finger)
Which type of loop is this, if on the right hand? Left hand?

10. Whorl
A plain or central pocket whorl have at least one ridge that makes a complete circuit. A double loop is made of two loops and an accidental is not covered by other categories.
Types
Plain
Central Pocket
Double Loop
Accidental

11. Can You See the Differences?

12. Primary Identification Numbers
Fingers are numbers 1 through 10 starting with the thumb on the
right hand and continuing through with the thumb on left hand.
Each finger is then given a point value as seen in the chart below.
1. right right right right right
thumb index middle ring little
6. left left left left left
thumb index middle ring little

13. Primary Identification (cont)
Set up a ratio of even numbered fingers over odd numbered, adding one in both the numerator and denominator.
2. right right left left left
index ring thumb ring little 1 +
1. right right right left left
thumb middle little index little

14. Fingers 2 8 1 2 16 8 4 1 16 4

15. Latent Prints
Latent fingerprints are those that are “hidden” and are not visible to the naked eye. These prints consist only of the natural secretions of human skin and require treatment to cause them to become visible.
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)
Apocrine--secrete cytoplasm and nuclear materials
Sebaceous --secrete fatty or greasy substances.

16. Lifting Latent Prints
Developing a print requires chemicals that react with secretions that cause the print to stand out against its background. It may be necessary to attempt more than one technique, done in a particular order so as not to destroy the print.
Powders--adhere to both water and fatty deposits. Choose a color to contrast the background.
Iodine--fumes react with oils and fats to produce a temporary yellow brown reaction.

17. Iodine Fingerprint

18. Ninhydrin Fingerprint

19. Lifting Latent Prints (cont)
Ninhydrin--reacts with amino acids to produce a purple reaction.
Silver nitrate--react with chlorides to form silver chloride, a material which turns gray when exposed to light.
Cyanoacrylate--”super glue” fumes react with water and other fingerprint constituents to form a hard, whitish deposit.
In modern labs and criminal investigations, lasers and alternative light sources are used to view latent fingerprints. It was first used by the FBI in Since lasers can damage the retina of the eye, special precautions must be taken and a filter used.

20. Cyanoacrylate Fingerprints

21. Other Prints Ears--shape, length and width
Face--pictures being used in Florida to find criminals
Voice--electronic pulses measured on a spectrograph
Feet--size of foot and toes; lines of the feet
Shoes--can be compared and identified by type of shoe, brand, size and year of purchase

22. Other Prints
Palm--lines can be identified and may be used against suspects.

23. Other Prints
Foot Prints are taken at birth as a means of identification for infants.

24. Other Prints Lips--display one of five common patterns
Short vertical lines
Long vertical lines
Rectangular lines that may crisscross
Diamond
Branching

26. Other Prints
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.

27. Other Prints
The blood vessel patterns may be unique to individuals. They are used for today various security purposes.

28. Other Prints: Iris Scans
Advantages: Unique to individual, easy to access, protected by cornea
Disadvantages: expense; distance; not left at a scene

29. “Fingered with the wrong print”
On March 11, 2004 a train was bombed in Madrid, Spain.
5 suspects
7 points of minutia
digital on-screen image
detained an American lawyer for 2 weeks

30. FBI Apologizes Brandon Mayfield was released
A series of mistakes led to the detaining of Mr. Mayfield
FBI and Spanish police conducted an investigation
How many points of minutia are necessary for a print to be considered individualized?

31. “FINGERED” Crazy Criminals
A New Jersey resident phoned police after finding her back door slightly ajar with a muddy palm print on the glass. When the officer questioned the woman, it was determined that she had been gardening. When he compared her hand with the lifted print, he had a match!!

32. PORTFOLIO
A portfolio is a collection of work that demonstrates what you know and can do. It shows your best work. In this unit, you will put together a portfolio of your work on making and lifting various prints. You will add to your portfolio as you work through the labs in class and put it in to a final form at home. You will be given both written instructions and an assessment list.