Read this to the detectives before the stations begin.
Detectives, we have a mystery! This morning we came in to get our cookies and... the cookie jar is EMPTY! Every single cookie is gone.
But whoever did it left clues behind. There's a muddy footprint on the floor. A single hair stuck to the jar. A bite mark in a leftover cookie. A fingerprint on the lid. And a note with the ink all smudged... plus a second note that looks completely blank.
That's where YOU come in. You are junior CSI detectives, and your job is to visit the evidence stations, study each clue with your detective tools, and remember what you find. Lock each clue in your detective brain - we'll go over them together when it's time to solve the case.
When every detective has gathered all the clues, we'll come back together and solve it on the big screen. Ready? Then let's find out... WHO TOOK THE COOKIES?
The Case of the Missing CookiesMaker Lab CSI
Station 1 - For Detectives
👣 The Footprint
The thief left muddy footprints! Find the shoe that made them. (Every muddy print came from the SAME shoe!)
Look closely at your muddy footprint clue.
What kind of foot made it? A paw? A monster foot? A giant cartoon shoe? Or a normal grown-up shoe?
Dig through the shoes and find the ones that match. Some look almost the SAME - look really close!
Look inside the tread lines: are they waves or hills?
Count the little tabs on the back: one or two?
Double check! A real detective looks again to make sure the print CAN'T be any other shoe.
Sure? Whisper what you found to a teacher or helper - and remember it: what kind of shoe, what shape is in the tread, and how many tabs!
Mirror trick! When you flip a shoe over to see the bottom, the pattern flips like a mirror - so the shoe that matches might be for the OTHER foot. Match the pattern, not left or right!
Whose shoe made the muddy print?
Station 1 - FootprintMaker Lab CSI
Station 1 - Helper Guide
👣 The Footprint Staff Only
The Match (the answer)
White Asics with rainbow accents. There are TWO nearly identical rainbow Asics in the pile - the real one has WAVES inside the treads (not hills/arches) AND TWO little tabs (one on the back of each of the two back-most treads). The decoy Asics has arches and only ONE tab. All clues this whole case point to a person, not a cartoon - this station just narrows the human shoes. On the Guess-Who / Suspect Filter boards this clue reads "Asics (waves, 2 tabs)" - use those exact words, because that's what the kids will pick at the big reveal.
How to run it (5 min)
Give each detective their own bagged muddy footprint. Tell the group up front: every muddy print is from the SAME shoe - one thief, many steps.
Have them size first with the calipers/ruler - rule out the tiny and giant shoes, leaving the normal-sized grown-up running shoes.
They'll spot the rainbow Asics fast. The trick is the two near-identical ones.
The air-dry clay impression is your detailed master reference in the clear box - point to it when the mud is too blurry to read.
End with the double check: teach them it means looking again to make sure the print CAN'T be any other shoe. When they're sure, they whisper the finding to you and keep it in their head for the reveal.
Say it like this
SAY: "Look at the back of your muddy print. Do you see little WAVES inside the lines, or little hills? Now find the shoe with waves... and count the tabs on the back - we want the one with TWO."
Mirror flip: holding a flipped-over sole next to a print reverses left and right - the RIGHT shoe will look like it matches a print the LEFT shoe made. Not every shoe in the bin has its pair, so when a kid says "it's backwards," that's the mirror - match the waves and tabs, not the direction.
If it stalls: have them press the bottom of the suspect shoe right next to the clay mold so the tread lines "lock together" like puzzle pieces.
Clue to remember: Asics running shoe (waves, 2 tabs)Tools: calipers, magnifying glass, clay master, 6 bagged printsTime: 5 min
Station 2 - For Detectives
🔬 The Hair
A hair was stuck to the cookie jar! What kind is it?
Look at the hair in the evidence bag with YOUR magnifying glass.
Is it fluffy FUR? Bright YARN? Or human HAIR?
What color is it? Colors can be tricky - hold it right next to the samples to be sure! Is it straight or curly?
Match it on the Hair Board. Double check - do the suspect hair and the sample hair have ALL the same things? Make sure it CAN'T be any other match - then whisper what you found to a helper and remember it.
Now take turns at the microscope! Look at a few slides, your own fingerprint, and the fabric of your clothes. What can the microscope see that your magnifying glass can't?
Is it an animal, a monster, or a person?
Station 2 - HairMaker Lab CSI
Station 2 - Helper Guide
🔬 The Hair Staff Only
The Match (the answer)
The crime-scene hair (Evidence Sample B) is human, curly, brown. This is the only station that rules out the cartoon/monster suspects - the fur/yarn samples are here so the kids can see the clue is a person's hair, not blue fur, green yarn, or red fuzz.
Brown, not black: kids often call the brown hair black - it IS brown. Have them hold it next to a truly black sample in good light. The close decoy is also brown, but it has coarse black hairs running through it in places (not everywhere, and at odd angles). The real hair is more consistent - not perfectly so, but that's the biggest distinction.
How to run it (5 min)
Detectives inspect Sample B with magnifying glasses, then match it on the Hair Board (Bluey blue fur, Grinch green yarn, Elmo red loops, Barbie straight blonde, and curly brown human).
Microscope (1-2 scopes, every kid has a magnifying glass): the hair ID happens with magnifiers + the Hair Board. AFTER the ID, kids take turns at the microscope - a few prepared slides, their own fingerprints, and the fabric texture of their clothes. Prompt: "What can the microscope see that your magnifying glass can't?"
Time-filler: find other interesting things to look at under the microscope - let the kids hunt for whatever they're curious about.
Say it like this
SAY: "Detectives, is this fluffy fur like an animal? Bright yarn like a cartoon? Or is it a real person's hair? ... It's curly and brown - that's HUMAN hair! So our thief isn't a furry friend."
Clue to remember: Curly Brown Human HairTools: magnifiers, Sample B baggie, Hair Board, microscope + slidesTime: 5 min
Station 3 - For Detectives
🦷 The Bite Mark
Someone took a bite of a cookie! Find the teeth that match.
Flatten your playdough into a "cookie."
Gently press a set of pretend teeth into your cookie.
Compare your bite to the real clue cookie in the box. Is the bite way too BIG? Way too small? Or just the right size?
Look close: are any teeth MISSING, or are they ALL there?
Find the teeth number that matches. Double check - make sure it CAN'T be any other teeth - then whisper it to a helper and remember it.
Which teeth made the bite?
Station 3 - Bite MarkMaker Lab CSI
Station 3 - Helper Guide
🦷 The Bite Mark Staff Only
The Match (the answer)
Teeth Model #5 - normal-sized human teeth with ALL teeth present - matches Cookie Clue A (the real air-dry-dough cookie). All 8 sets are human teeth (that part is easy), so this mostly confirms a person did it. The decoys are wrong in two ways: some are way too big or too small, and some are the right shape but have missing teeth. Drive the kids to three checks: human, normal sized, all teeth there. On the Guess-Who / Suspect Filter boards this clue reads "Normal human bite" - use those words at the reveal. Keep the real clue cookie in the clear box - look, don't touch.
How to run it (5 min)
Each kid flattens a playdough ball, presses a couple of the 3D-printed teeth (1-8) to make bite marks, and compares to the real Cookie Clue A in the box.
Split the group so they don't all try all 8: "Detectives 1-2 test teeth 1-3, 3-4 test 4-6..." Keeps it moving.
Optional: calipers to measure the bite width.
The teacher handles the real cookie at the final reveal and overlays Teeth #5 on it for the whole group - kids don't manhandle the fragile clue.
Say it like this
SAY: "All of these are people teeth - so which ones made THIS bite? Is your bite way too big? Way too small? Are any teeth missing? We're hunting for the one that's just the right size with ALL its teeth."
Clue to remember: Normal human bite (#5 - all teeth present)Tools: 8 printed teeth, playdough balls, Cookie Clue A in box, calipersTime: 5 min
Station 4 - For Detectives
🔍 The Fingerprint
A fingerprint was on the jar lid! Find the matching print.
Look at your clue fingerprint with your magnifying glass.
Is it a HILL (arch), a WAVE (loop), or a SWIRL like a target (whorl)?
Open your fingerprint book and hunt for the same shape. Can you find an EXACT match?
Which shape is it? Double check - make sure it CAN'T be the other shapes - then whisper it to a helper and remember it for the big reveal.
Now check YOUR fingers with your magnifying glass! What shapes do YOU have? Are all your fingers the same?
Compare with your friends - do they have the same shapes as you?
Arch, Loop, or Whorl?
Station 4 - FingerprintMaker Lab CSI
Station 4 - Helper Guide
🔍 The Fingerprint Staff Only
The Match (the answer)
The clue print is a WHORL - the round, spiral "bullseye/target" family. We match by family only (arch / loop / whorl), not the tiny details - hunting for an exact match in the book is a fun way to spend the time, but the family is the takeaway. What they must remember: it's a human WHORL. On the Guess-Who / Suspect Filter boards the clue reads "Whorl", and every whorl on the board is a human (animals, monsters, robots, and cartoons all have paw / claw / metal / glove prints instead) - so picking Whorl automatically means a person. On the younger kids' 8-print sheet, only one print is a whorl, so it's an easy win. Older kids use the bigger 48-print book and have to look a little closer.
How to run it (5 min)
Each detective gets a copy of the clue print + a magnifying glass.
Point to the reference poster: hill = arch, wave = loop, target/swirl = whorl. Teach them to look for the bullseye center.
They scan their book for the matching swirl, double check it, and whisper the type to you. (Family is all we need - skip ridge counting / the codes. Let them hunt for an exact match if they're into it - that's the time-filler.)
Wrap-up: kids type their OWN prints with the magnifier - which family is each finger? Are all their fingers the same? (Lots of people have a mix!) Then compare with friends.
Say it like this
SAY: "Look right at the middle of the print. Does it make a little hill, a wave, or a round target you could spin? ... A target - that's a WHORL! Now find a whorl in your book. When you've got it, check your own fingers - are all of yours the same?"
Clue to remember: Whorl (a human whorl)Tools: clue print copies, magnifiers, fingerprint books, arch/loop/whorl posterTime: 5 min
Station 5A - For Detectives
🧪 The Ink Race
The note's ink hides secret colors! Race them to find the match.
Draw one line on your paper strip with your marker.
Dip the bottom in the cup and watch the colors RACE up!
Black and gray ink are made of hidden colors. Which ones came out?
Compare to the crime-scene note. Did your ink make the same colors?
Found the marker that matches? Double check - make sure NO other marker makes those colors - then whisper the marker's NAME to a helper and remember it!
Which marker matches the note?
Station 5A - Ink RaceMaker Lab CSI
Station 5A - Helper Guide
🧪 The Ink Race Staff Only
The Match (the answer)
The note's pen separates into peach + blue streaks. The kids compare their racing strips to the dried crime-scene sample on the board and find the marker that makes the same peach + blue pattern. (Different black/gray markers split differently - that's the "aha.") The peach + blue pattern is how they FIND it - what they must walk away remembering is the marker's NAME: GRAY MONDO. That's exactly what the Guess-Who / Suspect Filter boards say ("Gray Mondo"), and it's the clue that narrows the board at the reveal.
How to run it (5 min)
Each kid draws one line on a filter strip with a different black/gray marker, then drops it in the shallow cup (alcohol, or water for washable markers - washables run fast).
While it climbs, do the science chat (below).
Compare the wet strips to the pre-dried crime-scene master sample on the board.
Wrap-up: when a kid finds the match, have them read the marker's name off the barrel and whisper "Gray Mondo" to you - that name is what they carry to the big reveal.
Say it like this
SAY: "This ink looks black... but watch! Black ink is a secret team of colors hiding together. The light colors run fast to the top, the heavy ones stay low. Which marker hid PEACH and BLUE - just like the note? ... That one! Check its name and whisper it to me - and keep that name in your detective brain."
Clue to remember: Gray Mondo (found by its peach + blue split)Tools: filter strips, black/gray markers, alcohol/water cups, dried master sampleTime: 5 min
Station 5B - For Detectives
🌺 Color-Flower Lab
Use the color science to make a flower to take home!
Draw circles and dots near the middle of your coffee filter with markers.
Drop water in the center and watch the colors bloom outward!
Put it on the tray with your name to dry.
Later it folds into a flower you get to keep!
What colors will YOUR flower make?
Station 5B - Color-Flower LabMaker Lab CSI
Station 5B - Helper Guide
🌺 Color-Flower Lab Staff Only
What this is
The take-home craft - no clue to solve here. The kids use the same chromatography science from 5A to make a tie-dye coffee-filter flower. Pure fun + a souvenir; it keeps the rotation flowing while 5A runs next door.
How to run it (5 min)
Each kid draws thick circles/dots near the center of a white coffee filter with washable markers.
Help them drop water into the center (dropper or wet paintbrush) - it bleeds the colors outward into a blended bloom.
Lay it on a name-labeled tray to dry. By the end of the session they're dry enough to pinch/twist into a flower to take home.
Say it like this
SAY: "Same magic as the ink race - the water makes the colors spread and blend. Draw your design, then we'll add water and watch your flower bloom!"
Clue to remember: none (craft)Tools: coffee filters, washable markers, water droppers, name trayTime: 5 min
The Big Reveal - Script (1 of 2)
🧮️ Solving It Together
Gather the detectives. Guess-Who board up on the big TV (PreK / K-3 level). Work the clues in THIS order so the footprint stays the grand finale.
Open
SAY: "Detectives, you gathered all the evidence - now let's catch the cookie culprit! Look at ALL these suspects. We'll use our clues to cross them off, clue by clue."
Driver notes: use ONLY the five clue tabs in this order - Hair color, Bite, Fingerprint, Marker, Footprint. Skip the Category and Gender tabs (Category = Human would shortcut the whole mystery). Tap the chip the kids call out.
Clue 1 - Hair
ASK: "What did the hair clue tell us?" (Curly brown HUMAN hair - we saw it with our magnifiers and the microscope.)
TAP: Hair color → Brown. SAY: "No brown hair? You're OUT! Bye Barbie - blonde! Bye Elmo - red fur! Bye Sonic - blue fur!" Watch out: a few furry friends HAVE brown fur - Scooby-Doo, Curious George, Yogi - so they're still in.
SAY: "Some furry friends snuck through with brown FUR. But we know our clue was human HAIR... so the next clue will catch them!"
Clue 2 - Bite Mark
ASK: "What made the bite?" (Teeth #5 - a normal human bite: not too big, not too small, all teeth there.)
TAP: Bite → Normal human bite. SAY: "People teeth! Every animal, monster, and cartoon still in gets crossed off NOW. A PERSON did this." (Overlay Teeth #5 on the real clue cookie here for the big "ooooh.")
Clue 3 - Fingerprint
ASK: "What was the fingerprint - arch, loop, or whorl?" (Whorl - the swirl target.)
TAP: Fingerprint → Whorl. SAY: "The Teacher's prints are arches - cross her off! And everyone with loops - out!" The Teacher, Steve, Bob the Builder, and more go out here.
The Big Reveal (1 of 2)Maker Lab CSI
The Big Reveal - Script (2 of 2)
🧮️ The Last Few... and the Twist
Clue 4 - The Marker (the ink race)
ASK: "The smudged note! At the ink race, the note's ink split into secret colors. Which colors?" (Peach and blue.) "And which marker makes peach and blue?" (GRAY MONDO!)
TAP: Marker → Gray Mondo. SAY: "Only suspects with a Gray Mondo marker are still in. Look how few are left!"
Clue 5 - The Footprint (the decider)
SAY: "Down to the last few - and look who's still here: the PRINCIPAL! She wears white Asics with rainbow accents... and so does the Cleaning Lady. The SAME shoes! Lots of people buy the same shoes. So how do we tell them apart?"
ASK: "Look at the muddy print. Did the tread have little WAVES or little hills? And how many TABS on the back - one or two?" (Waves + TWO tabs.)
TAP: Footprint → Asics (waves, 2 tabs). SAY: "The Principal's shoe has hills and only ONE tab. The muddy print has WAVES and TWO tabs..." It's the CLEANING LADY!
The Note Demo (front of room)
SAY: "But wait - why would the Cleaning Lady take ALL the cookies? Remember that second note that looked totally blank? It was written in SECRET INK. Watch what happens when I paint our detective solution over it..."
Swipe the turmeric solution across the baking-soda-ink note. The hidden words turn deep red/orange and appear.
READ TOGETHER: "The cookies were not allergy-safe! I moved them to the FRONT OFFICE so EVERY detective can have a treat. - The Cleaning Lady"
The Payoff
SAY: "She didn't STEAL the cookies - she was keeping everyone SAFE! She moved them so every single detective, even friends with allergies, could have a treat. Great work, detectives - case closed! Now let's march to the front office and get our cookies!"
Note for the teacher: have the real (safe) cookies waiting at the front office / your hand-off spot so the march pays off immediately.
