Blogger Nicole Martin

Fingerprints and Forensics with First-graders

Did you know with a few simple, inexpensive materials and some creativity you can create your own forensics lab for early elementary kiddos? You can! I lead a STEAM focused program at my library for first, second and third graders entitled Imagination Lab. The idea is that for four weeks in the fall, and again in the winter, we meet up after school to explore a variety of concepts that fit under the broad umbrella of STEAM. We experiment, sometimes I demonstrate, and we always create something to take home. In the past few weeks we have explored the science behind sound, polymers, and color, but my favorite topic may just have been forensics!

Inspired by the awesome Mad Scientists Club CSI program, I crafted my own 45-minute program for first through third grade patrons. I think this is a great program that can be easily modified for older children and held without breaking the budget purchasing special science equipment. The most fancy items you’ll need are magnifying glasses.

First, start off discussing what the word “forensics” means and what sorts of evidence might be helpful at a crime scene. Since my program was for early elementary school students, and I mostly have first graders in my group, we kept our discussion of crime scenes to stolen cookies, missing stuffed animals and library robberies.

Once you think everyone has a good basic understanding of the topic, you’ll want to get into the really fun part which is hands-on experimenting! Be sure to share some cool facts about fingerprints and using fingerprints to solve crimes before you start. You can find more neat facts in the great book Crazy for Science with Carmelo the Science Fellow by Carmelo Piazza . I have used this title for many program ideas, including our fingerprinting experiments. Check it out if you have it in your collection! Each chapter introduces a different branch of science and all the experiments are linked to science curriculum requirements for grades K through 3.

Below you can see some of the details from the program so you can easily replicate this at your library!

Fingerprinting Detective Supplies. image from Nicole Martin.
Fingerprinting detective supplies. Image from author.

Examine Your Fingerprints


  • Pencils
  • Clear tape ( I used book tape)
  • White paper (copier paper works fine)
  • Fingerprint pattern cards (You can find many images of typical fingerprint patterns online. I printed out the images on cardstock and distributed a card to each child.)
  • Mini-magnifying glasses
  1. Color a small square (about 4 inches) onto the white paper with a pencil.
  2. Press the top part of your index finger onto the pencil square, rolling it back and forth several times. You should have a very dirty finger!
  3. Press the clear tape firmly onto the dirty finger.
  4. Slowly pull the tape off the index finger and press it onto a clean sheet of white paper. The fingerprint should now be visible on the paper!
  5. Look at the details of the fingerprint with a magnifying glass. Try to identify what pattern each individual fingerprint is using the fingerprint pattern cards.
  6. Try this process with other fingers and compare patterns with your index finger as well as neighbor’s fingerprints.

Lifting Fingerprints 

Fingerpritns! Image by Nicole Martin.
Fingerprints! Image from author.


  • Small paintbrush
  • Corn starch (I measured a couple tablespoons into small plastic cups for each table to share.)
  • Clear tape ( I used book tape)
  • Dark black paper (construction paper or cardstock)
  • Paper plate (ideally coated paper plates, not just the regular white kind) 
  1. Rub the fingerprint part of your index finger down the side of your nose or in your hair/ scalp to get your finger dirty. (Gross, I know. But it works.)
  2. Press your oily finger against the center of the plate.
  3. Dip the paintbrush into the corn starch. You don’t need a lot! So be sure to shake off the extra powder before removing from the cornstarch.
  4. Use the brush to lightly “paint” the powder over the center of the plate where the fingerprint should be. The powder should stick to the oily fingerprint. Be sure to not press too hard or you will smear the fingerprint! This might take a couple tries to get right.
  5. “Lift” the fingerprint from the plate by placing a piece of tape firmly against the fingerprint. Then slowly and carefully peel the tape up.
  6. Place the sticky side down on the black paper.
  7. You should see the fingerprint on the paper!
  8. Take it farther and see if you can lift fingerprints off of nearby counter tops or door handles!
Mystery powder identification. Photo from Nicole Martin.
Mystery powder identification. Photo from author.

After our fingerprinting, we identified a “mystery powder” (aka powdered sugar) by observing chemical reactions. The kids loved it! I used instructions from that you can find and follow yourself here. If you have time you can also create some fingerprint artwork using washable ink pads and markers, but my little detectives had so much fun we ran out of time! The kids were so excited to be able to take their fingerprints and fingerprint pattern cards home to share what they learned.

There are so many more fun ideas for forensic experiments and extension activities out there- this is just the tip of the iceberg. I’d like to do this program again but set up a mock crime scene involving a stuffed pigeon, caution tape, and stolen cookies. Happy investigating fellow librarians!

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