katherine leger (order #2952986) 173.231.106 · dactyloscopy is the study of fingerprints. finger...

Katherine Leger (order #2952986) 173.231.106.226

Anyone for a Bit of Dactyloscopy?

It sounds prehistoric, and actually it is. It’s been around as long as

mankind. Or, at least what leads up to dactyloscopy. Put your finger on the

tip of your nose. Now move your finger out slowly, slowly until you can get

a good view of the tip of your finger. There they are! Little raised areas on

your skin that create unique patterns. They’re your fingerprints.

Dactyloscopy is the study of fingerprint identification. It’s the matching of

impressions to people.

Stop and Examine

Take a magnifying glass and study the patterns on your fingers.

1. What do you notice? 2. Are the patterns the same on each finger?

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

When you come in contact with objects and you leave impressions of the ridges of your fingers behind, these are called fingerprints. These ridges are a part of our largest organ. Can you name it? It’s our skin! Yep, the skin of a human is its largest organ. Just like the heart and lungs, it’s vital to our survival. The ridges at the end of our fingers (actually our entire palms) are raised in order to sense vibrations when we touch objects with texture. They help us grab and hold on to things with our fingers. Each person has their own set of unique prints. No two individuals are alike. Not even twins. They’re a sort of ID card in nature.

How do we leave these impressions behind? Our skin has natural lubricating agents so it won’t all dry up and blow away. We’d look quite odd (not to mention yucky) if we didn’t have our skin holding us together.


Besides, it protects our bodies from intrusion by bacteria and germs. When we touch objects, we leave a bit of this lubricant or natural oil behind. By a simple process we can ―lift‖ those oily impressions to have a better look at them. If we have dirt or some other substance that our fingers can transfer to things we touch, we leave an even more discernable impression.

If they play by the rules, experts can identify who left behind their fingerprint. No guessing in fingerprinting! There is a clear set of rules that have to be followed to determine if a fingerprint belongs to a particular person. If you are approached by an individual who says to you, ―Pardon me, sir, but I believe you left your fingerprints on this object,‖ he better be sure they’re yours.

An entire system of fingerprint identification exists in law enforcement. Oftentimes, when a person goes to get a job, they have to go through a background check. They go to a local police station and have their fingertips inked and printed. Thanks to technology, we now have something called Live-Scan that you can just place your fingertips on and it can record the impression your fingers make. Your fingerprints go into a huge data base with your personal information. In this way, the person hiring you can be sure you’ve never been arrested for a particular crime.

All kinds of factors are involved in identifying fingerprints. What was left behind so that the fingerprint can be identified? Did your fingers smudge the print as they touched the object being studied? Did you use your whole finger tip or just a small part of it? Was the object that was touched smooth or bumpy? A fingerprint on a glass is easier to detect than one on certain kinds of fabric. If you’re going to identify someone by their fingerprints, you need to be very careful. Was the fingerprint left behind from the natural oily and sweaty secretions of your body (a latent print) or was it left behind by something you touched earlier like barbecue sauce (a patent or visible print)?

Fingerprints fall into three general types of patterns. Each group bears the same general characteristics or family resemblance. The three general pattern types may be further divided into subgroups by means of smaller differences existing between the patterns in the same general group. The arch group includes the plain arch and the tented arch. The loop group includes the radial and ulnar loops. The whorl group includes four types of whorls, the plain whorl, central pocket loop, double loop, and accidental whorl.

arch loop whorl


http://www.answers.com/topic/plain-whorl

http://www.answers.com/topic/accidental-whorl



Look at the following fingerprints.

The first fingerprint from the left looks like you took a rainbow and squeezed the two sides together. Trace its path with your finger. It curves up and immediately curves down without much space in between. It is called a ―loop‖. Loops can lean to the right or left or be exactly in the center of a finger print. The second fingerprint from the left has a ridge print that curves like more of a sloppy rainbow, comes up to the upper part of the fingertip, and then curves back down. This is called an ―arch‖. Another example of an arch follows. Arches can form a little tent-like impression at the base of the print like in the picture of the third print. The one on the far right swirls round and round like a cinnamon bun. It’s called a ―whorl‖.

Here are the same prints with their descriptive names.

Loop Arch Tented Arch Whorl

These fingerprints fall under the basic groups: 1. loop 2. arch 3. whorl The third one above is another example of an arch.


http://en.wikipedia.org/wiki/File:Loop.jpg

http://en.wikipedia.org/wiki/File:Arch.jpg

http://en.wikipedia.org/wiki/File:Tented_arch.jpg

http://en.wikipedia.org/wiki/File:Whorl.jpg

http://en.wikipedia.org/wiki/File:Loop.jpg

http://en.wikipedia.org/wiki/File:Arch.jpg

http://en.wikipedia.org/wiki/File:Tented_arch.jpg

http://en.wikipedia.org/wiki/File:Whorl.jpg

This page gives you a clearer view and outlines the pattern of the ridges.

Keep in mind that the tented arch is another example of an arch.

What are the three general types of fingerprints?

loop, arch, and whorl

Is the tented arch another group?

No, it is an example of the arch group.


Fast Facts about Fingerprints

Dactyloscopy is the study of fingerprints.

Finger prints were used in Ancient Babylon on clay tablets for

business transactions.

The first state in the United States using fingerprints for criminals was

New Mexico.

No two fingerprints have ever been found alike in billions of comparisons.

Even identical twins have different fingerprints.

The governments of all countries worldwide have used fingerprints for identification.

The International Association for Identification (IAI) was established in 1915.

The use of fingerprint identification provide more evidence in court than any other forensic technique.

A person’s appearance can change but not their fingerprints.


Some Great Extension Ideas

Create a fingerprint card for all of your family members. Study the patterns and whether they fall under which group: loop, arch, or whorl.

Are there hereditary similarities between your prints and those of your family members?

Create a ―mock‖ crime scene getting one of your family members to put a fingerprint dipped in graphite (pencil smudging) on a hard, smooth surface in your house. Have them to keep it a secret from you as to who touched the surface. When the ―coast is clear‖, come out with your handy fingerprint cards to determine who your culprit is. You can have fun with all types of this activity. Be sure to not let your fingerprint cards rub against each other. The fingerprints might smudge. You may want to attach them to a display board.

Use this same process using toe prints.

Research information of the careers of people who work with fingerprints: police officers, detectives, FBI, or fire inspectors.

Research the history of fingerprinting and create a timeline.

Did you know the Koala had fingerprints so close to a human’s that it takes a skilled examiner to tell them apart?

Dog’s noses leave a print much like a fingerprint. No two dogs have the same nose print.


Activity #1

Taking Your Own Prints

Visible Prints

Skills:

Observing

Comparing and contrasting

Classifying

Supplies:

Clean White Paper with Square to Create Your ―Graphite Pad‖

Fingerprint Card for Displaying Your Fingerprints

Pencil

Two Inch Long Strips of ¾ Inch Wide Transparent Tape (10 of These Will Be Used)

Magnifying Glass (Optional)

1. Take your pencil and fill the square on your sheet of paper with a dark area.


Keep filling it in until it is dark with graphite. Graphite is the inside of a pencil that makes the mark when you write.

2. Press your left thumb on the square of graphite you created. Rub your thumb around in order to get plenty of graphite on it.

3. Press your left thumb against the sticky side of a piece of transparent tape.

4. Carefully place the transparent tape against the card provided in the square labeled ―left thumb‖ with the sticky side against the card. The edges on the tape will stick to the card leaving a good impression of your left thumb’s fingerprint. It’s a good idea to clean your thumb before applying the tape. It keeps the process from getting messy. However, if you are careful and keep your thumb away from the process of applying the tape, you’ll be fine. You can even get assistance from someone else.

5. Feel free to practice this process until you can get a good print by trying it on your clean, white sheet of paper first.

6. Once you have a print of your left thumb on the card, complete the same process with your other fingers. Try not to move the tape on the card or the print will smudge. You’ll get better at this the more you practice.

7. Study your prints and answer the following page of questions.


What kinds of patterns do you see? Feel free to create your own words in describing your fingerprints like curvy, pointed, loopy.

__________________________________________________________________________________________________________________________________________

After you have studied your prints, use the page with examples of ―official‖ names for patterns (loops, whorls, and arches).

__________________________________________________________________________________________________________________________________________

In which direction do the loops curve—toward the thumb or toward the pinkie finger? This can get tricky. The fingerprint you created on the tape is completely opposite to your actual fingerprint because you made a copy and then flipped it over. If you had pressed your fingers straight to the card without the tape, you would have your true fingerprints. Flipping them with tape just gives you a chance to study them. This matters when you begin to be specific about naming the loops.

__________________________________________________________________________________________________________________________________________

Compare the size of the patterns on your handout to your own. For instance, you might try to count how many ridges make a loop.

__________________________________________________________________________________________________________________________________________


Activity #2

Taking Your Own Prints

Without Tape

This is the same activity as Activity #1 only you are going to press your graphite covered fingers straight to the card without the use of the tape. This gives you a true fingerprint as well as more practice.

Skills:

Observing


Classifying

Supplies:

Clean White Paper with Square to Create Your ―Graphite Pad‖

Fingerprint Card for Displaying Your Fingerprints

Pencil

Magnifying Glass (Optional)

1. Take your pencil and fill the square on your sheet of paper with a dark area. Keep filling it in until it is dark with graphite. Graphite is the inside of a pencil that makes the mark when you write.

2. Press your left thumb on the square of graphite you created. Rub your


thumb around in order to get plenty of graphite on it.

3. Press your left thumb in the square marked ―left thumb‖ on the fingerprint card. Try to keep this process clean. You can wipe your fingers with a damp cloth in between prints if you need to.

4. Once you have a print of your left thumb on the card, complete the same process with your other fingers. Try not to move your finger on the card or the print will smudge. You’ll get better at this the more you practice.

7. Study your prints and compare them to the prints you took using transparent tape in Activity #1. They are the same prints only mirror images. Remember these are the actual prints you would leave behind if you touched something.

This time, when you study your prints, determine which type of fingerprint you have more of: loop, arch, or whorl.

______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


Here are some great examples of fingerprints. Taking what you’ve learned about the three main groupings of fingerprints, loops, arches, and whorls, determine which group these fingerprints fall under. Write your notes to the right of each fingerprint.

1.

2.

3.


Activity # 3

Taking a Latent Print

Fingerprints must be removed carefully and transported to the crime lab. They are then compared to the database of fingerprints on file. One way that detectives locate fingerprints is by dusting for them. This type of print is called a latent print. What the person left behind was the natural oils or sweat in their skin. Natural oils lubricate our skin to keep it from drying out. When we touch objects, we leave oily impressions behind. These fingerprints are coated with a special powder by forensic scientists and then lifted and taken to the lab for identification.

This activity will give you an opportunity to lift a latent print.

Skills:

Observing


Classifying Supplies:

Drinking glass Bit of oil to make your finger more oily and your fingerprint easier for you to lift Soft brush like a makeup brush or very soft paint brush Transparent tape Clean, white card Magnifying glass (optional) Patience!


1. Press an oily (barely much oil) or sticky finger on the side of a drinking glass.

2. Using a soft brush like one of your mom’s old makeup brush (ask her first) or a very soft paint brush, dust the fingerprints lightly with cocoa powder or baking powder. Be careful to not move the fingerprint with the brush. Barely touch it. Blow on it softly to get the excess powder off. Practice this until you can get a good covering. If you smudge it, clean the glass and try again. Forensic scientists have to practice to get this right.

3. Press the sticky side of transparent tape to the fingerprint and place the tape sticky side down on a clean, white card. Examine the fingerprint with a magnifying glass if you have one.

Latent prints are made visible through a variety of techniques. There are powders, special light sources, and glue fuming.

Look at the prints on the next page. Forensic scientists look at the details labeled to determine if the fingerprints are a match to a crime scene. See if you can find details like those labeled in the latent print you just lifted.


Use the following page to record the types of fingerprints displayed. Explain why you chose the type you did.


Types of Fingerprint Patterns

a and b __________________________________

Why? __________________________________________________________________________________________________________________________________________

c and d __________________________________

Why? __________________________________________________________________________________________________________________________________________

e, f, g, h __________________________________

Why?

______________________________________________

______________________________________________

______________________________________________


Vocabulary

Classify

To sort into groups by likenesses and differences

Latent

Present and not able to be seen but capable of

becoming visible. Used to describe fingerprints that

are not visible until they are dusted with chalk or

other powders, or until they are lit with a laser

Visible

Capable of being seen by the eye without help


Taking the Three Groupings of

Fingerprints a Step Further

(a–b) Loop patterns:

(a) ulnar loop the loop leans toward the ulnar

bone in the arm

(b) radial loop the loop leans toward the radial

bone in the arm

(c–d) Arch patterns:

(c) plain arch

(d) tented arch a visible ^ (tent) appears in the

arch

(e–h) Whorl patterns:

(e) plain whorl

(f) central pocket loop

(g) double loop

(h) accidental whorl


http://www.answers.com/topic/ulna

Cut these strips and place them in your “Fast Facts about Fingerprints” pocket on panel one of your

lapbook. The title for the pocket is your first strip.


These are your pockets. You’ll just tip all around the back edges with a glue stick leaving the tops open.

The first pocket is your “Fast Facts about Fingerprints” pocket. Next to that, is a short pocket for your

compare/contrast fingerprints. Lastly, you have your “Fingerprint Files” pocket.


Above is your “Fingerprint Details” booklet. You can place your own fingerprints inside covered with

invisible tape and point out some of the finer details of fingerprints. Or, you can use any of the

fingerprint images in this eBook to glue in and to note if you find samples of the details displayed on the

cover of your booklet.


Above, are your fingerprint matchbooks. We’ve left them free of labels so that you can determine their

pattern and label them yourself. Inside, write a description of that particular type of fingerprint. You fold

these much like a matchbook cover and tuck the long piece into the smaller. We use small Velcro dots to

keep them closed, but a staple very close to the edge on the fold at the shorter end will give you a good

“tucking location”. We buy the little Velcro dots in bulk and find them indispensable. Write us at

[email protected] and we’ll be glad to pass on the information about where to order

them. You can also take Velcro circles and cut them into small wedges with a sharp pair of scissors. Keep

your scissors cleaned of the adhesive build up with alcohol or fingernail polish remover.


mailto:[email protected]

These strips are for your compare/contrast pocket. You can write on the back your conclusions of if they

have patterns in common or are different. This is great for using a magnifying glass as well.


This booklet provides an up-close look at more details of a fingerprint. Forensics experts have to study

these to make determinations. Place one of your own fingerprints inside the booklet or an image in the

eBook and see if you can locate and label these distinctive areas.


Here are your samples of common fingerprint patterns to place on panel two of your lapbook.

Remember that a tented arch is just another style of arch. The three most common patterns are loop,

arch, and whorl.


This is a sample of a forensic kit. When you make your own, take a photo of it and place it inside this

booklet. Also, give details of how you built your kit and improvised.


You will use this form above to collect fingerprints of friends and family. Use the invisible tape to keep

the prints from smudging. Store these in the “Fingerprint Files” pocket on panel three of your lapbook.


Design the front of your lapbook using your own drawings, writings, or anything from the eBook. You

can use our picture of Steve-O above, our Sizzling Science Student. Have fun adding to your lapbook and

making it uniquely yours. Just like you and your fingerprints, your lapbook should be one-of-a-kind.


Lapbook Photos

Fingerprint Matchbooks Four samples of fingerprint patterns Build Your Own Forensics Kit Booklet

Compare/Contrast Fingerprints Up-Close Labeled Fingerprint Fingerprint Files

Fast Facts about Fingerprints Detailed Fingerprints Booklet


katherine leger (order #2952986) 173.231.106 · dactyloscopy is the study of fingerprints. finger...

Documents