Collect and analyze evidence
Collect and analyze evidence from a mock crime scene using observation, fingerprint dusting with safe materials, measurements, and logical reasoning to identify the culprit.
Step-by-step guide to collect and analyze evidence from a mock crime scene
How Do Children Use Evidence In Scientific Inquiry? - Childhood Education Zone
Step 1
Gather all the Materials Needed and bring them to a small table or tray.
Step 2
Clear the table area so you have a clean space to make your mock crime scene.
Step 3
Place the 3 small objects around the table to create the mock crime scene.
Step 4
Look carefully at the scene and draw a simple map in your notebook showing where each object is.
Step 5
Measure the distances between the objects with the ruler and write the numbers on your map.
Step 6
Put a small pinch of cocoa powder on a paper plate to use for fingerprint dusting.
Step 7
Gently dip the soft brush into the cocoa and lightly brush the surface of the first object to reveal any fingerprints.
Step 8
Press a small piece of clear tape gently onto the powdered fingerprint to lift it.
Step 9
Stick the lifted tape onto a piece of white paper to preserve the fingerprint.
Step 10
Repeat Steps 7 to 9 for the other objects to preserve each fingerprint.
Step 11
Ask three family members to each make a sample fingerprint by lightly touching cocoa on the plate then pressing their fingertip onto white paper.
Step 12
Write each sample maker’s name on the back of their paper so you know who is who.
Step 13
Use the magnifying glass to compare the preserved fingerprints to the sample prints and look for matching ridge patterns.
Step 14
Decide which sample best matches the evidence using your comparisons and measurements and write your conclusion in the notebook.
Step 15
Share your finished investigation on DIY.org.
Final steps
You're almost there! Complete all the steps, bring your creation to life, post it, and conquer the challenge!
Help!?
My family doesn't have cocoa powder, a soft brush, or a magnifying glass—what safe substitutes can we use for Step 5 and Steps 7–11?
Use cornstarch or talc‑free baby powder instead of cocoa for Step 5, a clean soft paintbrush or makeup brush for Step 7, and a smartphone camera with zoom or reading glasses in place of the magnifying glass for Step 11.
If I brush and don't see any fingerprints or the tape won't lift them, what should I try?
Use very light strokes with the soft brush and less cocoa in Step 7, press the clear tape gently and lift at an angle in Step 8, and if prints still fail check that the object surface isn't oily or try a finer powder before repeating Steps 7–9.
How can I adapt the activity for a 4-year-old, an 8-year-old, and a 12-year-old?
For a 4-year-old simplify Steps 4–6 by having them place and count stickers on a prearranged scene, for an 8-year-old let them dust and lift prints with supervision in Steps 7–9 and compare with the magnifying glass in Step 11, and for a 12-year-old have them take precise measurements with the ruler in Step 6 and write a detailed conclusion in Step 12.
How can we make the investigation more advanced or personalized before sharing it on DIY.org?
Enhance the activity by photographing each object with a ruler scale after Step 6, labeling each lifted print on the white paper from Step 9 with the sample maker's name from Step 10, and adding a typed report of your measurements and match from Step 12 to upload in Step 13.
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Facts about forensic science for kids
🍫 For kid-friendly fingerprint demos, household powders like cocoa or cornstarch can safely reveal prints on shiny surfaces.
🧪 Forensic science can sometimes identify people from very small samples — like a single drop of blood or a few skin cells.
🔎 No two people (except identical twins) have the same fingerprints, so prints are a powerful way to match who touched something.
📏 Putting a ruler or scale next to evidence in photos shows real size later — professionals always include a scale for accurate measurements.
🕵️♀️ Crime scene investigators photograph, sketch, and measure everything carefully — tiny details and measurements can change the story of what happened.
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