Hands-On Forensics Investigation Using Blood Evidence & DNA Fragments.

Who Kidnapped the School Mascot?

Turn your classroom into a crime lab with this fully customizable forensic science activity! With just a few quick edits, you’ll have a personalized mystery that has students testing blood samples and analyzing DNA to uncover which of your coworkers is guilty of kidnapping the school mascot.

🔍 How it Works:

• Personalize the case by adding your school mascot’s name and the names of your coworkers.

• Students become forensic scientists, using blood typing and DNA testing to crack the case.

• For extra fun, add coworker photos to the included “mugshot tag” for a lineup of suspicious suspects!

🧪 Easy Teacher Prep:

1. Create “blood samples” with milk, food coloring, and simple household liquids (vinegar for positive reactions, water for negatives).

2. Prep DNA strips ahead of time (or use the quick-edit version with names for less prep).

3. Hand students the case file and watch them investigate like real detectives.

✨ Why Teachers Love It:

• Completely customizable for your school

• Highly engaging—students forget they’re doing a lab!

• Takes less than one class period (perfect for a fun, fast-paced day)

• Great way to connect biology concepts like blood typing and DNA analysis to an exciting real-world application

Your students will be laughing, testing, and collaborating as they work to solve the crime. By the end, they’ll not only know “whodunit,” but they’ll also have sharpened their lab skills in a way they’ll never forget.

Grade & Course Recommendations

⭐ Primary Target:

Middle School Life Science (Grades 6–8)
Perfect fit for:

• 7th grade science

• 8th grade life science

• Middle school forensics electives

• End-of-unit genetics mystery day

⭐ Secondary Use (Optional):

9th Grade Introductory Biology
Best used as:

• A fun break-before-vacation lab

• A station activity

• A practice or review tool

• A crime-scene hook

Cross-Curricular Connections & Extensions

ELA

• Students can write a crime report, forensic justification, or detective narrative.

• Claim–Evidence–Reasoning extensions fit perfectly with MS writing expectations.

Math

• Pattern recognition

• Logical elimination

• Simple data comparison (band patterns, clotting results)

Tech / Digital Literacy

• Students may create digital suspect boards or case files.

Forensics / Criminal Justice (Electives)

• Introduction to evidence-based reasoning and simple forensic techniques.

Optional Extensions

• Add fingerprint cards, fiber evidence, or shoe tracks.

• Turn the investigation into a 2-day case-solving project.

• Include a mini-lesson on ancestry, ABO inheritance, or co-dominance.

Join the Lesson Laboratory and Teach for Tomorrow!

NGSS Standards

Middle School Performance Expectations

MS-LS3-1

Develop and use models to describe why structural changes in genes affect proteins and traits.
✔ DNA fragment-cutting model fits perfectly.

MS-LS3-2

Use evidence to support explanations for patterns of inheritance.
✔ Blood type patterns & genotype logic directly support this.

MS-LS1-2

Develop models to describe the hierarchical organization of interacting systems.
✔ Blood typing investigates one element of the circulatory system.

High School Performance Expectations

• HS-LS1-1 – Structure & function of DNA, enzymes, and molecular interactions

• HS-LS3-1 – DNA structure & inheritance; mutations and restriction site patterns

• HS-LS3-2 – Patterns of inheritance supported by blood typing co-dominance

• HS-LS1-2 – Using models (restriction enzymes + gel electrophoresis)

Science & Engineering Practices (SEPs)

• Analyzing & Interpreting Data: blood typing reactions, fragment patterns

• Constructing Explanations: why the suspect’s DNA matches

• Developing & Using Models: restriction enzyme simulation

• Engaging in Argument from Evidence: defend the “guilty” suspect

Crosscutting Concepts (CCCs)

• Patterns: matching blood type and DNA patterns

• Cause & Effect: mutations → different fragment patterns

• Structure & Function: blood antigens, restriction sites

• Systems & System Models: the circulatory system and DNA as analyzable systems

Common Core Standards (ELA & Math).

ELA

RST.6-8.3 – Follow multistep procedures (blood typing).
RST.6-8.7 – Interpret visual representations (DNA bands).
WHST.6-8.1 – Write arguments supported by evidence (accusing the suspect).
WHST.6-8.9 – Use evidence from informational text.

Math

6.SP.B – Use sample data to draw conclusions.
7.RP.A – Reasoning with proportional/logical patterns.