T. Trimpe 2006 http://sciencespot.net/ Name: ____________________________ 1. Fingerprint Principles According to criminal investigators, fingerprints follow 3 fundamental principles: 1. A fingerprint is an ____________________ characteristic; no two people have been found with the ___________ same fingerprint pattern. 2. A fingerprint pattern will remain ___________ for the ___________ of an individual. 3. Fingerprints have general characteristic ___________ patterns that allow them to be systematically identified. 2. Fingerprint Classes There are 3 specific classes for all fingerprints based upon their visual ___________________: arches, loops, and whorls. Each group is divided into smaller groups as seen in the list below. 3. Examples Arches are the simplest type of fingerprints that are formed by ridges that enter on one ________ of the print and exit on the ___________. No ________________ are present. Loops must have one _________ and one or more _________ that enter and leave on the same side. These patterns are named for their positions related to the _________ and ________ bones. ________________ Plain Tented ________________ Radial Ulnar ________________ Plain Central pocket Double loop Accidentical ___________ Arch Ridges enter on one side and exit on the other side. _____________ Arches Similar to the plain arch, but has a spike in the center. Loops = ______% Whorls = ______% Arches = ______% _____________ Loop Loop opens toward the thumb or radius bone on the right hand. ____________ Loop Loop opens toward the little finger or the ulna bone on the right hand.
Transcript
T. Trimpe 2006 http://sciencespot.net/
Name: ____________________________
1. Fingerprint Principles
According to criminal investigators, fingerprints follow 3 fundamental principles:
1. A fingerprint is an ____________________ characteristic; no two people have been
found with the ___________ same fingerprint pattern.
2. A fingerprint pattern will remain ___________ for the ___________ of an individual.
3. Fingerprints have general characteristic ___________ patterns that allow them to be
systematically identified.
2. Fingerprint Classes
There are 3 specific classes for all fingerprints based upon their visual ___________________:
arches, loops, and whorls. Each group is divided into smaller groups as seen in the list below.
3. Examples
Arches are the simplest type of fingerprints that are formed by ridges that enter on one ________
of the print and exit on the ___________. No ________________ are present.
Loops must have one _________ and one or more _________ that enter and leave on the same
side. These patterns are named for their positions related to the _________ and ________ bones.
________________
Plain
Tented
________________
Radial
Ulnar
________________
Plain
Central pocket
Double loop
Accidentical
___________ Arch
Ridges enter on one
side and exit on the
other side.
_____________ Arches
Similar to the plain arch,
but has a spike in the
center.
Loops = ______%
Whorls = ______%
Arches = ______%
_____________ Loop
Loop opens toward the thumb or
radius bone on the right hand.
____________ Loop
Loop opens toward the little finger
or the ulna bone on the right hand.
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Whorls have at least one ____________ that makes (or tends to make) a complete __________.
They also have at least ____________ deltas. If a print has more than two deltas, it is most
likely an ____________________.
4. Identify each fingerprint pattern shown on the class notes.
A. ____________________ C. ____________________ D. ____________________
B. ____________________ E. ____________________
5. Follow your teacher’s directions to document your
fingerprints on the My Prints worksheet. Use your notes
and a magnifying glass to identify the pattern in each one.
_____________ _________ whorls are made up of any two loops
combined into one print.
_______________ whorls contain two or more patterns (not including
the plain arch), or does not clearly fall under any of the other
categories.
Draw a line between the two deltas in the plain and central pocket whorls shown below. If
some of the curved ridges touch the line, it is a plain whorl. If none of the center core touches
the line, it is a central pocket whorl. Label each fingerprint below.
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Match the prints inside the question mark to the prints found around the border of the page.
Fingerprints 149
ACTIVITY 6-1STUDY YOUR FINGERPRINTS
Objectives:
By the end of this activity, you will be able to:1. Identify your fingerprints.2. Compare your fingerprints to those of your classmates.
Time Required to Complete Activity: 40 minutes
Materials:
clear, adhesive tape 3⁄4 inch in widthrulerpencil3 × 5 cardmagnifying glass
Safety Precautions:
No special precautions
Procedure:
1. On a lined 3 × 5 card, rub the end of a graphite pencil in a back-and-forth motion, creating a patch of graphite about 2 by 3 inches.
2. Rub your right index finger across the graphite patch, gently rolling from side to side so that the fingertip becomes coated with graphite from the first joint in the finger to the tip, and from fingernail edge to fingernail edge.
3. Tear off a piece of clear adhesive tape about 2 inches long. Carefully press the sticky side of the tape onto your finger from the edge of your fingernail across your finger pad to the other side of your fingernail.
4. Gently peel off the tape.5. Press the tape, sticky side down, into the box provided on the next
page. 6. Examine your fingerprint using a magnifying glass.7. Compare your fingerprint to the pictured samples. 8. Identify whether your fingerprint pattern is a loop, arch, or whorl.
1. ________________ _______________ are impressions left by friction ridge skin on a surface, such as a tool
handle, glass, door, etc.
2. Prints may be collected by revealing them with a dusting of ______________ ______________ and then lifted
with a piece of _____________ ____________.
3. What is the most common type of animal hair that is used to make brushes? ___________________
4. Some investigators use ___________________ powder and UV lights to help them find latent prints on multi-
colored or dark surfaces.
5. _________________ powder can also be used to reveal latent prints. This type of powder works better on
_________________ surfaces or _________________ baggies and containers.
6. The __________________________ fuming method (often called the super glue method) is a procedure that is
used to develop latent fingerprints on a variety of objects.
7. Watch the video to answer these questions.
During fuming the super glue heats up and attaches to the ______________ ___________ in the
fingerprint.
The evidence is placed in a super glue ________________ to develop the prints.
8. ______________________ is a chemical that bonds with the amino acids in fingerprints and will produce a
_________ or ____________ color. It is used to lift prints from surfaces such as paper and cardboard.
Follow your teacher's directions to lift your fingerprint and tape it in the space below.
My Latent Print
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Name __________________________
Make fingerprints for each hand and then classify them according to the types presented in class.
T. Trimpe 2007 http://sciencespot.net/
Name _______________________________ Step 1: Classify your fingerprints and record the number of each pattern below. Your total should equal 10! Arches = _________ Loops = __________ Whorls = _________ Step 2: Complete the chart below by recording the total number of each pattern for the class. The expected averages are 60% for loops, 35% for whorls, and 5% for arches.
Pattern # Total Prints %
Arches
Loops
Whorls
How do our prints compare to the expected averages? Step 3: Complete the chart below by recording the total number of each pattern for the males and females in the class.
Pattern # Males # Females Total Prints %
Arches
Loops
Whorls
Which pattern is most common pattern among the males in this class?
Which is most common pattern among the females?
How do the averages for each sex compare to the expected averages?
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The Science of Ridges Name ____________________________
1. ___________________ is the study of the uniqueness of friction ridge structures and their use for personal
identification.
2. As we have learned in our first lesson, a fingerprint is made of a series of ________________ and ________________
on the surface of the finger. The uniqueness of a fingerprint can be determined by the ________________ of ridges and
valleys as well as the ________________ points, which are points where the ridge structure changes.
3. When minutiae on two different prints match, these are called points of ______________________ or points of
______________________. At this point there is _______ international standard for the number of points of identification
required for a match between two fingerprints. However, the United Kingdom requires a minimum ______________
points while Australia requires _________________.
5. Ridge Characteristics - Draw the different ridge characteristics listed below.
Dot or Island
Enclosures
Short Ridge
Bridge
Ending Ridge
Hook
Fork or
Bifurcation
Eye
Specialty
Core
Delta
Crossover
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6. How many ridge characteristics can you identify in this fingerprint? Use a hand lens and highlighter to help you
identify the characteristics and then label each one.
Try It! - Analyze the fingerprints on your “My Prints” worksheet to see how many ridge characteristics you can
find.
Which ridge characteristics did you find in your fingerprints? List them below and mark the two most common ones with
a star.
Fingerprints 151
ACTIVITY 6-2GIANT BALLOON FINGERPRINT
Objectives:
By the end of this activity, you will be able to:Create a giant fingerprint for use in studying various ridge patterns.
Introduction:
Ridge patterns help make fingerprints unique and identifiable. By study-ing your own thumbprint and those of your classmates, you will be able to identify these patterns.
Time Required to Complete Activity: 20 minutes
Materials:
1 large white balloonfingerprinting inkpadhand soap or moist wipespaper towels
Safety Precautions:
Before doing this activity, deter-mine if any students are allergic to latex. If so, you can substitute purple nitrile gloves in place of the latex balloon.
Procedures:
1. Slightly blow up a large balloon or half inflate a large balloon.2. Ink your thumb from thumbnail to thumbnail and past the first joint.3. Carefully roll your thumb over the balloon from nail edge to nail edge,
leaving a thumbprint. Make sure your print is situated about a quarter of the way from the top, and two-thirds of the way from the bottom.
4. Fully inflate the balloon and examine your thumbprint.5. Identify your thumb pattern as a loop, whorl, or arch.6. Examine the balloons of your classmates and identify the ridge types
you find.7. Deflate your balloon and save it.
What you will need to do this experiment: a white balloon and an inkpad.
By the end of this activity, you will be able to:1. Explain the significance of fingerprint evidence.2. Describe how to take and identify latent fingerprints.
Introduction:
Every person has a unique set of fingerprints, even identical twins. Whenever you touch a surface without gloves or other protection, you leave behind an invisible fingerprint. Law enforcement agencies use various fingerprint powders and chemicals to help visualize these telltale prints.
Time Required to Complete Activity: 40 minutes
Materials:
newspaper black dusting powder adhesive tape 3⁄4 inch widedusting brushclothmagnifying glassdrinking glass, watch with glass face, other pieces of glass or Plexiglas®soap or premoistened handwipes paper towels
Safety Precautions:
Cover the work area with newspapers.Handle the dusting powder with care, because it can be very messy.
Procedure:
1. Cover the worktable with newspaper.2. Wipe off a drinking glass, watch glass, piece of window glass, or
Plexiglas® with a clean cloth.3. Take your thumb and run it along the side of your nose or the back of
your neck. These areas of your body are rich in oils and will help lubri-cate the ridges of the thumb to produce a clearer print.
4. Choose an area on the glass object and touch the glass with your thumb. Use a paper towel or other type of cloth in your other hand to prevent leaving other fingerprints. Be careful to avoid placing any other finger-prints in this area.
5. Dip the dusting brush lightly into the fingerprint powder. Place the brush between your hands and gently twist the brush, so that the bristles spin off excess powder near the surface of the object you are dusting. A latent (hidden) fingerprint should begin to appear. Continue to dust lightly, touching the surface until you have exposed as much
By the end of this activity, you will be able to:1. Describe and identify different types of fingerprint minutiae.2. Identify different minutiae patterns found in fingerprints.
Time Required to Complete Activity: 30 minutes
Introduction:
Latent fingerprints found at crime scenes are usually incomplete (partial) prints. Investigators need to examine the characteristics of a fingerprint very carefully. The simple identification of a whorl, loop, or arch is not suf-ficient. Other markers (minutiae) need to be identified.
Materials:
examples of recovered latent fingerprints red pen
Procedure:
1. Study the picture below. It shows fingerprints obtained from a suspect and a crime scene (mirror). Notice how the investigator has labeled the points of comparison with the same letter on the rolled ink print and the latent print from mirror. Use the chart of characteristics in your text to identify the specific characteristics.
Rolled ink print taken from suspect (left) and latent fingerprint lifted from the crime scene (right).
2. Identify each of the patterns labeled in the ridge pattern diagram. Refer to the chart on minutiae in the text.
A. _______________________________________________ B. _______________________________________________ C. _______________________________________________ D. _______________________________________________ E. _______________________________________________
3. Examine each of the fingerprints below. Using a red pen and referring to the chart in your text, circle the minutiae pattern and then label it with the appropriate number.
By the end of this activity, you will be able to:1. Match the latent crime scene print to one of the suspect’s fingerprints.2. Justify your match by identifying the fingerprint pattern along with as many fingerprint
minutiae found in both the crime scene print and the suspect’s fingerprint.3. Circle the common minutiae points on both the crime scene print and the suspect’s
fingerprint.
Introduction:
Using a red pen, encircle and identify as many minutiae reference points shared by the crime scene fingerprint and the suspect’s fingerprint.
