How to Use Fingerprint Analysis in a Middle School Science Project

Teach students about fingerprint analysis with interactive activities.

Teach students how criminologists use fingerprint analysis in a middle school science project. For over 100 years law enforcement officials have relied on the analysis of latent fingerprints to held solve crimes. Guide your students in conducting a forensic science experiment in the classroom and making a set of their own fingerprints. The inexpensive experiment requires just a few standard classroom supplies and a magnifying glass.

Things You'll Need

• Glass cups
• Ink pads
• Index cards
• Transparency or laminating paper
• Talcum powder, cornstarch or cocoa powder
• Magnifying glass
• Paint brushes
• Masking tape

Instructions

1. Discuss with the students how each set of fingerprints is unique, which is why police officers look for the impressions at crime scenes. You can also include in the pre-project lesson different reasons the students may have their fingerprints used during the course of their lives. You can use an ink pad and blank index card to create a classroom fingerprint index before moving onto the analysis aspect of the project. If you contact a local law enforcement agency in advance, a representative may visit your class to talk about fingerprinting and make a set of fingerprints and identification packet for the students to give to their parents.

2. Tell students there are two different types of fingerprints, visible and latent. Latent fingerprints are typically left on items due to sweat and organic material found on the skin. Law enforcement agencies use a process called fuming to reveal latent fingerprints. The bottom layer of the skin, known as the dermis, creates the unique ridges on a person's fingers. Fingerprints are first visible when a growing baby is still in the womb. As soon as seven months after a baby is conceived, arches, whorl and loop patterns are visible. Even though no two people have identical fingerprints, similar patterns do run in families.

3. Turn your classroom into a crime scene with a mini-mystery for the students to solve. A day before your planned experiment have each student touch an identical glass cup. Use transparency sheets or pieces of laminating paper cut to measure 8 by 11 inches. Help each student create a full set of fingerprints on their sheet of paper by using an ink pad. Have each student to write their name on a piece of masking tape and label their glasses. Place your fingers inside each cup to handle and place one on each students desk. You can use the experiment as a small group project to save time and reduce the amount of supplies needed.

4. Instruct students to sprinkle powder onto their cups to reveal the latent fingerprints. If the glass is a dark color use cornstarch or talcum powder. Light or clear glasses will require the use of cocoa powder to make fingerprints become visible. Small paint brushes can be used to lightly brush the powder onto the glass. Students will pass around the labeled transparency fingerprints charts for comparison when analyzing the fingerprints. Using a magnifying glass, students will look closely to the distinctive patterns in the prints to reveal which classmate touched their cup.

References

• Home Training Schools: Forensic Science Experiments
• Interpol: Forensic Fingerprints
• Science Buddies: Are Fingerprint Patterns Inherited