Forensics for Kids




Introduction: Forensics for Kids

This instructable is being entered into the DIY Summer Camps Contest. Ordinarily it would be split into three instructables: Crumbs, Stains and Tool Marks but is offered as a larger intractable to cover the many days of summer. I chose forensics as a way for kids to explore the details of their surroundings.

All forensics lessons that are currently available discuss a crime and often times a violent crime such as murder with blood splatter which may be uncomfortable subjects to explain to younger kids.

I modified real forensic concepts into Forensic for Kids to allow younger kids to build crime fighting skills that directly relate to their world without having to explain violent crime scenes. I start off the individual activities with material that the kids are already familiar with such as their favorite snacks and later introduce foods they may not have seen before but can explore the properties of the new material.

The series is broken up into individual concepts such as crumbs (trace material), stains and residues (blood splatter and trace), tool marks and impressions (matching properties of tools and impressions made in clay).

I hope to expand in the future to include chromatography, tracks and fingerprints. There is currently a lot of information available on those subjects but as you can see in crumbs and stains I am looking at creating innovative ways to make it fun and appealing for younger kids.

All these activities can tie into one big crime investigation which are especially fun for birthday parties or weekend get togethers.

Step 1: Materials - Crumbs

Crumbs was inspired by my nephew that likes to move around when he eats. He eats in bed, on the couch and leaves trails of crumbs from one place to another.

Materials: Various snack products like cookies, chips, crackers, bread, instant noodles, anything that leaves crumbs and include some that do not leave crumbs.

Optional - Magnifying glass, ruler, Sharpie marker to label location of the evidence and time collected

Optional for crumbs - Clear tape to pick up crumbs and index cards to place the clear tape with evidence on. Alternatively you can just pick up the crumbs with one end of the tape and double over so that you can see both sides of the crumb.

Optional for larger evidence- Plastic utensils or tweezers to collect evidence, plastic sandwich bags to store evidence

Optional - Stuffed Animals in different places of the house or pictures of suspects and where they were at.

Step 2: Scene of the Crime - Crumbs

I will suddenly make an exclamation that a terrible event has happened! Then point to the pile of crumbs. We round up the suspects and search their area. We look through the closet, under the bed, along the window, in the garbage can, through the drawers, sofa, etc... looking for food products until we find a match. This is especially fun when you place things that get a laugh such as a giant inflatable animal that falls out of the closet or a pair of socks in the freezer. Usually the item of interest is a half eaten pack of snack size cookies or chips. In order to match the crumbs; well we have to make crumbs which is very exciting for the kids. I believe all kids are naturally gifted at making crumbs and can show you how it is done. The crumbs are then checked with a magnifying glass for a match and the suspect is required to clean up the mess.

Ta da! Another mystery solved. Hurray! Let's enjoy the snacks.

Variation - Use particles or any small objects that kids can find a match to. Examples include shells at the beach, leaves, rocks or soil from the garden, seeds, bits of food, candy, thread / yarn, fur, fake insects...there are infinite variations.

Variation - Change location from indoors to outdoors such as a park, beach or garden...I usually make the evidence larger so that it is easier to find than crumbs that might be confused with the particles already in the location. At the sand box, I like to bury plastic toys for them to dig and find. Leaves, rocks, flowers, soil or twigs are especially nice for kids to explore in the garden. You can give them tweezers or disposable chopsticks, spoon and plastic sandwich bags to collect and label the evidence.


For very young kids that have trouble matching, just hide a toy and have them find it.

Step 3: Forensics for Kids - Stains

This activity is similar to crumbs and allows kids to explore properties of household products.This activity was inspired by all the dirty stains that kids accumulate on their shirts.

Materials: Container to distribute liquid (examples include: syringe, water gun, spoon, chopstick, squeeze bottle, straw, toothbrush, paint brush...

A liquid / sauce / anything that will leave a stain. Examples include beverages, condiments, markers, candy, popsicles, mud, shampoo, lotion...infinite variations.

Step 1:

Shoot the liquid from the container onto a piece of paper or paper towel. You can also try flicking the liquid from things like a paint brush, tooth brush...Do you get different stains if the paper towel is hung up vs being placed on the floor or inclined surface.

We are investigating whether or not the same information obtained from blood / liquid splatter applies to other liquids or sauces of various compositions and viscosity.

Was the drop dropped vertically or at an angle? Which direction did it come from? How fast and far away was it delivered? How long has it been there? Was the opening of the container big or small?

Variation: Instead of liquid stains, leave a glob of something like toothpaste, shampoo, ketchup, mustard, salad dressing...Can they match to a specific brand when choosing between 3 or 4 similar colored materials? They may also smell the stain to obtain additional information.

Variation: Use a different type of fabric or surface to make the stain instead of a paper towel. Such as on the sidewalk, on a cotton shirt, on a rain jacket, wood flooring, marble countertop, shower wall, paper or plastic bag...infinite possibilities.

Step 4: Forensics for Kids - Tool Marks and Impressions

This activity is inspired by all the restless kids that love to chop, cut and smash things.

Materials: Something to cut that leaves fine details (play dough, cheese, hard jello...) The play dough was a little bit soft so something slightly stiffer. Clay seems to be to hard.

Tool (plastic knife, scissors...but not to sharp for the kids)

Use one of the tools to cut the play dough in half. The kids use the other tools to try and cut the play dough in a way that leaves the same cut mark. Can any of tools be ruled out? What patterns do you observe? Which ones leave a rough or smooth surface? Can you tell where the force was applied (straight down or angled)?

Variation: Something left an impression. Smoosh half of any object that has nice detail (flashlight, walnut, rock, marker, bottle...) into the play dough and pull it out. Kids try to match size and shape and depth (force / pressure applied) from objects found at the crime scene.

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    4 years ago

    This is a very original idea, one could envision a Montessori- type day school for children with the concept as the core, you'd no doubt have a wait-list of anxious moms who'd want to enroll their offspring. ☺

    Well done!