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. Plain Tented Radial Ulnar Plain Central pocket Double loop Accidentical Loops = % Whorls = % Arches = % 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. 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 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. 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. T. Trimpe 2006 http://sciencespot.net/
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. 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. 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. 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. T. Trimpe 2006 http://sciencespot.net/
Match the prints inside the question mark to the prints found around the border of the page. T. Trimpe 2006 http://sciencespot.net/
ACTIVITY 6-1 STUDY 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 width ruler pencil 3 5 card magnifying glass Safety Precautions: No special precautions Procedure: 1. On a lined 3 5 card, rub the end of a graphite pencil in a back-andforth 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. Cengage Learning (all) Arches 5% Whorls 30% Loops 65% Fingerprints 149 45866_06_c06_p132-157.indd 149 12/1/07 10:21:53 AM
Tape your fingerprint into the space provided and identify its pattern type. Which hand? Which finger? Fingerprint pattern? Data Collection from Class: Complete the table: Count the number of students showing each of the three types of fingerprint patterns and place those numbers in the Data Table. Data Table Number of students showing trait Total size of class (This will be the same total for each column) Percentage of class showing the trait (Divide the number of students with trait by the total size of class, then multiply by 100%) Loop Whorl Arch Experts say this percentage should be 65% 30% 5% Questions: 1. Did the class percentage agree with the value given by experts (yes or no)? Explain your answer using data for support. 2. Describe how to improve this data-collecting activity so that your results might be more reliable. 150 Fingerprints 45866_06_c06_p132-157.indd 150 11/30/07 12:12:19 PM
Name 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 multicolored 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 T. Trimpe 2008 http://sciencespot.net/
Name T. Trimpe 2006 http://sciencespot.net/ Make fingerprints for each hand and then classify them according to the types presented in class.
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? T. Trimpe 2007 http://sciencespot.net/
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. 4. AFIS = 5. Ridge Characteristics - Draw the different ridge characteristics listed below. Core Ending Ridge Short Ridge Fork or Bifurcation Delta Dot or Island Eye Hook Crossover Bridge Enclosures Specialty T. Trimpe 2007 http://sciencespot.net/
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. T. Trimpe 2007 http://sciencespot.net/
ACTIVITY 6-2 GIANT 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 studying your own thumbprint and those of your classmates, you will be able to identify these patterns. Time Required to Complete Activity: 20 minutes What you will need to do this experiment: a white balloon and an inkpad. Materials: 1 large white balloon fingerprinting inkpad hand soap or moist wipes paper towels Cengage Learning Safety Precautions: Before doing this activity, determine 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. Fingerprints 151 45866_06_c06_p132-157.indd 151 11/30/07 7:03:12 PM
ACTIVITY 6-3 STUDYING LATENT FINGERPRINTS Objectives: 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 wide dusting brush cloth magnifying glass drinking 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 lubricate 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 fingerprints 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 152 Fingerprints 45866_06_c06_p132-157.indd 152 11/30/07 7:03:31 PM
ACTIVITY 6-5 IS IT A MATCH? Objectives: 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 sufficient. 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). A Cengage Learning B C D E Fingerprints 155 45866_06_c06_p132-157.indd 155 11/30/07 7:28:29 PM
Fingerprint Ridge Patterns 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. Arthur Cengage Learning 1. Bifurcation 2. Island ridge 3. Ending ridge Doris Cengage Learning 4. Eye 5. Spur or hook 6. Ridge ending Alice Cengage Learning 7. Double bifurcation 8. Island ridge Suspect Cengage Learning What patterns can you find in this print? 156 Fingerprints 45866_06_c06_p132-157.indd 156 11/30/07 12:14:16 PM
ACTIVITY 6-6 FINGERPRINT MATCHING Objectives: 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. Time Required to Complete Activity: 30 minutes Crime-scene print Suspect A Suspect B Suspect C Suspect D Suspect E Suspect F Suspect G Suspect H All photos Cengage Learning Fingerprints 157 45866_06_c06_p132-157.indd 157 11/30/07 12:14:36 PM