Forensic Science
Forensic Science
Activities
Fingerprinting | Shoe Prints | Lip Prints | Handwriting analysis |
| Chromatography |
Fingerprinting
Have students read the handout Fingerprinting Background Information. Divide the class into groups of 4-5 students. Give each student a sheet where they can record their group's fingerprints. The easiest way to record fingerprints is to have students rub an area on a piece of paper with a pencil. The students then rub their fingers over the graphite on the paper. Next, apply a small piece of tape to the finger, lift and place the tape on the sheet of paper. You will then have a record of each student's fingerprints. You may also place the tape on a sheet of overhead projector film and then you can project the image of a fingerprint for the entire class to see. Make a copy of the fingerprinting record sheet for each group so that you may use it in this activity and future crimes. Choose one set of fingerprints to be those of the culprit in each case the students solve involving fingerprints.
The case:
Yesterday, someone put salt in the sugar bowl on the teacher's table in the lunchroom. Later in the day a large jar containing a mysterious white substance was found stashed behind the curtain on the stage. The substance was later determined to be salt. Upon investigation, a set of fingerprints was found on the jar. Your job is to examine the fingerprints and decide if anyone in your class is the culprit in this crime..
Additional Fingerprinting Activities:
Dusting for fingerprints: Rub your finger across your nose or through your hair. Make a fingerprint on a clean glass. Sprinkle cocoa powder over the glass and brush the powdered area with a fine paintbrush to remove the excess powder and expose the print. Place a piece of transparent tape over the print and lift the print from the glass. If you use a dark glass or piece of plastic, use talcum powder instead of cocoa to lift the print.
Give each student a small piece of metal or plastic. Have them rub their finger over their nose and make a fingerprint on the object. Place the object in a jar and place several drops of superglue into the jar. Be sure not to get the superglue on the print. Close the lid of the jar and wait approximately 30 minutes. The print will appear to be white.
Shoe Prints
To begin this activity, you need to have each student bring in an old shoe to use for making prints the week before the activity begins. Paint the bottom of each shoe with black tempera paint and then place the shoe on a large sheet of white paper to make a print of the sole of the shoe. The next activity is to make a plaster cast of individual students' shoes. Have each student bring in a shallow box about the size of a shirt box. The lid of a large shoebox will work also. Fill the box with wet Plaster of Paris. Have the student press down on the plaster with his old shoe. This will make an imprint of the sole of the shoe in the plaster. Keep the shoe in the plaster until the plaster hardens, then remove the shoe. Make one extra set of shoeprints for one or two of the shoes. These will be the prints of the culprit in the crimes you present to the class to solve.
Lip Prints
Read the Lip Prints Background sheet and then complete the activities below.
Before class have 10 people make a lip print on an index card. Label the back of each card Suspect 1, 2, 3, etc. Have the person designated as the guilty party make two copies of their lip print. Label the back of the second lip print "guilty party." Have the students compare the lip prints of the suspects to the guilty party.
The Case:
A student at Dannelly School has been writing graffiti in lipstick on the girl's bathroom mirror. She has been signing her work with her lip print. The custodian is having to clean the mirror several times each day to remove the graffiti and is getting tired of this prank. For the first hour of school he makes a list of the girls seen leaving the girls restroom. The principal has each of the ten girls seen leaving the restroom make their lip print on an index card to compare to the lip print on the bathroom mirror. Your task is to compare the lip prints of the suspects to the lip print found in the bathroom and identify the culprit. Record your findings on the lip print classification chart.
Additional Lip Print Activities:
Before class, have someone make a lip print on a paper towel. Have several lipsticks which are similar in color to use in the experiment. Students will make chromatograms of the various types of lipsticks to determine which lipstick was worn by the guilty party.
Cut the lip print on the paper towel into strips. Give one strip to each group of students. Next, give each group 5 plain strips of paper towels. Have each group make a lipstick smear on one end of each blank paper towel with one of the five suspect lipsticks and label them #1-#5. Place 1/2 inch of fingernail polish remover (acetone) in 6 different glasses for each group. Loop the paper towel strip over a pencil. Place the pencil over the top of the glass with the paper towel strip hanging down the center of the class. Make sure the lipstick end of the paper towel strip is toward the acetone. Have the end of the paper towel touch the acetone. Observe how the lipstick separates into different colors on the paper towel. Compare the chromatograms of the five suspect lipsticks to the chromatogram of the lip print. Use the lipstick chromatogram sheet to record your findings.
Handwriting Analysis
Read the handwriting background sheet then complete the activities below.
Before class, have 10 different people (not your students) write the following on a piece of notebook paper in cursive. Have one person write the note twice.
Dear Mrs. (insert the teacher's name),
Please excuse Allison from school yesterday. She was sick with a high fever.
Sincerely,
Mrs. Smith
Place a number on the back of each letter. Make sure you keep a record of whose letter gets what number.
The Case:
Allison was absent from school on Monday. When she returned, she gave the teacher an excuse she said her mother wrote. The teacher was suspicious because the handwriting looked more like a student's than an adult's. Allison finally admitted that she had played hooky from school on Monday and had had one of her friends write the note for her. She refused to tell who had written the note. She said she didn't want to get anyone else in trouble. Your job is to examine the note and determine who wrote the ransom note. Record your findings on the Handwriting Analysis sheet.
Chromatography
Read the chromatography background page and then complete the following activity.
In this activity, students must decide which ink pen wrote a ransom note. Before class, write a fake ransom note with a black ink pen on a piece of filter paper. You could make the note say anything you want, such as.... "If you want the classroom digital camera returned, put $250.00 in an envelope and leave it under the big plant in the school lobby at 2:30. Come alone and leave as soon as you leave the money." Wrap a piece of masking tape around each of 5 black ink pens and number them from 1 to 5. Make sure you remember which number wrote the ransom note.
The Case:
Someone has stolen the classroom digital camera! We received this ransom note this morning. I think this ransom note was written by a student in the class using one of the ink pens on the teacher's desk. We are going to use chromatography and try to determine which pen wrote the ransom note.
Cut 1/2 inch by 5 inch strips of filter paper. Give each group of students 5 blank filter papers and one filter paper with a line 1/4" from the bottom written with the ransom note pen. Have the students make a line 1/4" from the bottom of each filter paper strip with one of the five suspect ink pens. Have them write the number of each ink pen at the top of the filter paper strip in pencil.
Place 1/2 inch of fingernail polish remover (acetone) in 6 different glasses for each group. Loop the filter paper strip over a pencil. Place the pencil over the top of the glass with the filter paper strip hanging down the center of the class. Make sure the ink print end of the paper towel strip is toward the acetone. Have the end of the filter paper touch the acetone. Observe how the ink separates into different colors on the paper towel. Compare the chromatograms of the five suspect ink pens to the chromatogram of the ransom ink pen. Use the ink pen chromatogram sheet to record your findings.
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Copyright © 2000 S. Seagraves