Fun With Fingerprints

Detectives and forensic scientists collect fingerprints at the scenes of mysterious events, which can help them solve the mystery. Did you know that collecting fingerprints is super simple? All you need is a few tools you already have at home, and you can put your detective skills into practice.


Blank sheets of paper

Cocoa Powder

Soft round paint or makeup brush

Magnifying Glass


Scotch Tape

Washable Markers or your ink pad

These activities will teach us how to collect fingerprints. This technique is not all that much different from how real detectives collect fingerprints at scenes of mysterious events. This might take a little practice, but once you get the hang of it, you can show off your sleuthing skills.

Note: These activities are just for fun. Don’t try this outside your home, your friends’ home, or a safe place supervised by a groovy grown-up. And never interfere with the work of real detectives and investigators. It’s against the law!

Activity 1: Transferring to Tape

1). Using your ink pad or washable markers, cover the tip of your ring finger and pinky with ink.

2). Stick a piece of Scotch tape to your ink-covered fingers and press firmly.

3). Remove the piece of tape and stick it to a blank piece of paper. With your magnifying glass, you’ll be able to see your fingerprints and identify whirls, arches, and loops.

Ready for the next step?

Activity 2: Dusting for Prints

1). Rub your hands together to bring out the oils from your skin.

2). Place as many fingertips as you’d like onto a mirror, and press flat against the glass.

3). Pour a small amount of cocoa powder on top of the prints and dust with the paint or makeup brush. Blow away any excess powder.

4). Stick a piece of Scotch tape on each print and lift. The fingerprint will stick to the tape. Ta Dah!

Here’s how this works…our skin produces oil that keeps it smooth and healthy. This is why when you wash your hands a lot, which removes the oil, your skin might feel dry and cracked and you might need to apply moisturizer—don’t stop washing your hands, though! It’s very important. When we touch objects, we leave oil behind from our unique fingertip patterns. The fine cocoa powder we used to dust the prints sticks to the oil left behind by your finger when you touched the mirror and made the prints visible. When detectives are looking for a person who might have witnessed or been involved in a mysterious event, finding and collecting fingerprints is one way to help solve the puzzle.

Note: If you have super clean fingers, you can make your fingerprint stickier by pressing your finger or thumb into honey first. Then wipe off any excess honey and make your fingerprints.

More Family Fingerprint Fun!

Want to take your Super Sleuth skills to the next level? Gather your family members and show them all how to do Activity 1 using all their fingertips. Then collect fingerprints around your house using the steps in Activity 2 with your cocoa powder, brush and tape.  Great places to look for fingerprints are drink glasses, countertops, doorknobs, and faucets.  Write down each place you find the prints. Once you’ve collected as many as you can find, use your magnifying glass to compare the prints with the ones in Activity 1 to see who left their fingerprints in each place. You might even be able to figure out which fingers tend to leave the most prints.

Use your imagination to create mysteries that you and your family can have fun solving!

For more challenging play try a monthly-themed Groovy Lab in a BoxThere is no better way to educate your STEMists than to keep their minds screen-free, design learning to create and solve, through the engineering design process and STEM-related activities. Furthermore, our monthly box activates thinking, questioning, inquiring and original creation as we guide children through scientific inquiry and engineering design process.

For more about forensics and a mystery you can solve check out our “Magical Mystery” box for a Lesson in Forensics. During your ENGINEERING DESIGN CHALLENGE you will learn about  forensic science, cryptography, spy messaging, and much, much more.

A groovy approach to hands-on Next Generation Science Standards,  design based learning… Groovy Lab in a Box!

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