The detective badge can be such a fun way to experiment with science while having fun. I originally wanted to complete this as an event with decorated lab stations and "scientists", but Covid changed our plans. With a few adjustments, we completed this badge online with requests from the girls to play it again at a later time, hopefully in-person!
Plot: Someone has stolen the cookies from the warehouse before our first scheduled cookie booth. The suspects left behind a crumpled note with an encrypted message, a pen with a fingerprint, a shoe impression in the mud, and saliva on a coffee cup.
Station 1: Observation Station
Play a round of "Kim's Game" to see just how strong your observation skills are and discuss ways to improve them. If you are in-person, have everyone bring in a couple of their favorite objects and grab a sheet or tablecloth large enough to cover everything. Uncover everything for a minute and then cover it back up. For online meetings, share an image with a collection of clip art objects for a minute and then stop sharing. Give them a minute to write down as many objects as they can remember. Ask them if they incorrectly remembered any objects. Could their eye-witness testimony be incorrect?
Station 2: Cybersecurity Lab
The crumpled note left at the crime scene is written in Morse code on one side and substitution cipher on the other. Decode the messages to find out the motive of the thieves. An easy way to write a message in Morse code is this online translator. For the second part of the note I used a very simple substitution cipher for my troop with a basic swap of A=Z, Z=A, B=Y, and Y=B. The message in the note is the motive for stealing the cookies.
Station 3: Chromatography Lab
Multiple pens were left with the crumpled note. Use the science of chromatography to see which pen was used to write the note, then analyze the fingerprint left on the pen! Not a single one of the pens I had in my various drawers had the cool colors you would want to see for this experiment. After a bit of research, I ordered the below black felt tip markers and pipettes from Amazon (affiliate link).
The second pens can be any gel pen, ballpoint, or sharpie. I also ordered coffee filters but didn't really like them for this experiment so I switched to paper towels. To make it look cooler, I used my Cricut to cut the paper towels and write in Evidence #1. The girls were able to complete the experiment in just minutes without an elaborate set-up and no mess. Check out the results of my tests with various pens below and three drops of water on each test strip:
The
AEN Art pen looked nice but doesn't come in a pack of just black and doesn't fit my Cricut Maker.
Station 4: Fingerprint Lab
Use a pencil and tape or transfer paper to identify your fingerprint types. Then compare the fingerprint left at the crime scene with the suspect list. Most girls had completed this at school at some point. I cut up some 1 inch squares of transfer paper for them to use instead of giving them each rolls of tape. I grabbed some online images of different types of loops, whorls, and arch.
Station 5: Shoeprint Lab
A shoeprint was left in mud outside the warehouse. Compare the tread and size with the suspect list to identify the thief. This was a simple comparison of size using a ruler and matching tread patterns. I gave them a sheet of paper and asked them to outline their own shoes and compare the shape with others.
Station 6: DNA Lab
Saliva was left on a coffee cup in the warehouse. Learn about DNA and then compare the sample with the suspect list. There are some neat science experiments to extract the DNA from a strawberry I would have loved to complete given more time, but this experiment seemed too complex to complete online with my troop at this time. Maybe we can do it for the Cadette Special Agent badge in a couple years when we have in-person meetings again.
Finally, complete the search warrant form and find out if you have solved the crime!
I spent many hours grabbing clip art and formatting the activities into a printable workbook for our online meeting. If you would like to skip the work, please head over to Etsy to download the copy I created for a small charge:
Etsy Digital Download
Want me to put everything together and ship it to you?
Etsy Detective Kit
Have fun with this badge, I know our troop really did!