Teacher Project overview

 

One of the first things investigators look for at the scene of a crime is prints.  They hope to find fingerprints on items in the house, footprints in the soil outside the house and even tire prints.  One type of print that you do not commonly hear about is the lip print.  You have probably seen lip prints at your home.  Women who wear lipstick often leave their lip prints on drinking glasses. 

          Lips, like fingers, have special features that belong only to the individual making the print.  Like fingerprints, no two lip prints are exactly the same.  Therefore, a lip print can be used to identify an individual. 

          Many people’s lips have parts of at least two patterns.  This allows for great variety between the lips of different individuals.  When a woman wearing lipstick leaves a print on a surface, an investigator can take that surface to the lab for evaluation or life the print.  When lifting the print, the investigator places talcum powder near the print and spreads it in both directions over the print with a soft brush.   After the print is photographed, a piece of clear plastic tape can be placed over the print and then peeled away.  The lip print will be transferred to the tape.  This print can then be compared with lip prints from suspects. 

 

Category: CSI Lip Printing

 

Lips display five common patterns:

1. Short vertical lines
2. Long vertical lines
3. Rectangular lines that may crisscross
4. Lines that form diamond patterns
5. Branching lines like those in a plant root

 

Brief Description:  

 

Duration: 20 minutes on Day 1 and 40 minutes on Day 2.

 

Goals:  To understand the process required to use lip printing in crime scene investigations

 

Preparation Game: To assist the students in understanding the patterns associated with lip prints.

Match the lip prints

 

 

Objectives:  You will compare lipstick prints to determine who committed the crime.

 

Teacher resources:

·       6 tubes of red lipstick (all the same color)

·       48 pieces of plain white paper, 13 cm X 13 cm

·       Stereomicroscope

·       Ruler

·       Pencils

 

Student resources:  same as teacher resources

 

Procedure:

Day 1: Creating the evidence with six volunteer students

1)    Apply red lipstick to your lips.

2)    Fold a piece of white paper in half, and use it to blot your lips.  Be careful not to smudge the resulting lipstick print.

3)    Repeat steps 2 and 3 five more times on five different pieces of paper so that you have placed your lipstick prints on six pieces of paper.

4)    Write your name on a sheet of notebook paper.  Carefully fold the six lipstick prints in the notebook paper and give them to your teacher, who will decide which set of prints represents those found at the crime scene.

 

Day 2: Identification of the criminal

1)    The six volunteers who made the lip prints are the six suspects in the diamond theft.  Today, these volunteers should:

a.     Write their names on the chalkboard

b.     Apply the red lipstick and make one lip print for the class.  At the bottom of the print, each volunteer should write her name.

2)    Each student, including the suspects, is a member of one of the investigative teams.

3)     Examine the crime scene lipstick print under the stereomicroscope.

4)     Sketch the crime scene print – noting its special characteristics- on the crime report sheet.  Note the line patterns in the lips.

5)     Use the stereomicroscope to examine on e of the prints made today by the six suspects.  Draw this print on the crime report sheet.  Note key features about the print and record the name of the suspect.

6)     Repeat step 5 until you have drawn and made notes about all six suspects’ lip prints.

 

Assessment:

Post lab Questions

1)    Who left the lipstick print on the glass in Janice’s bedroom?

2)    Explain what patterns in the lip prints helped you to identify the person who left her glass in the bedroom

3)    Is this enough evidence to convict the suspect of theft?

4)    Select someone in your group (who was not one of the six suspects) to make a lip print.  Describe the patterns you see in that person’s lips.

 

Post lab Answers

1)    Answers will vary depending on whose prints the teacher selects on Day 1.

2)    Answers will vary, but should indicate specific patterns or combinations of patterns.

3)    No.  She may have been in the bedroom, but there is no proof that she stole the jewelry.

4)    Answers will vary, depending on the print characteristics.

 

Internet resources:

1)    http://www.forensic-evidence.com/site/ID/ID00004_10.html

2)    http://web.sunybroome.edu/~chm_dept/lipprints.html