Case Briefing Slides Classified
Mystery Masterminds
Case #2026-001: The Missing Mascot
Detective Agency HQ
The Incident Report
Date: January 17, 2026
Location: Riverside Middle School
What We Know
"Rusty the River-Rat" (the school mascot suit) has disappeared.
Last seen: Friday afternoon, 3:30 PM, in the gym storage locker.
Discovered missing: Monday morning, 7:00 AM.
"This isn't just a prank. The Big Game is this Friday. We need Rusty back!"
— Principal Miller
Your Mission
Analyze witness statements, find contradictions, and identify the thief before the weekend!
Detective Skill #1
Assessing Reliability
Objectivity
Does the witness state facts, or are they influenced by their feelings about someone else?
Consistency
Does their story match other evidence? Do they change their story mid-sentence?
Perspective
Was the witness in a position to actually see or hear what they claim?
Warning: Not every witness tells the truth. Some are mistaken. Some are lying.
Suspect Profiles
Coach Henderson
Head Football Coach
Maya "The Artist" Chen
Yearbook Photographer
Principal Miller
The Big Boss
"Open your Evidence Folders. Let's begin the interrogation."
Witness Statements Packet Witness Statement Dossier
Case Ref: #2026-001 | Subject: Mascot Theft
Name: ________________________
Date: _________________________
Confidential
Witness Statement #1: Principal Miller
"I checked the gym storage locker at exactly 3:30 PM on Friday. The Rusty the River-Rat suit was hanging right where it belongs. I locked the gym doors myself and walked back to my office. I spent the rest of the afternoon until 5:00 PM catching up on emails. I didn't see anyone in the hallways, but I did hear some loud music coming from the gym around 4:00 PM. I assumed it was Coach Henderson and the team practicing, so I didn't investigate."
Key Detail:
Location at 3:30 PM: Gym
Observation:
Loud music at 4:00 PM
Witness Statement #2: Coach Henderson
"We didn't have practice on Friday because of the rainy weather. I stayed in the gym to organize the equipment. Around 3:45 PM, Maya Chen came in to take some photos for the yearbook. She stayed for about 20 minutes. I was with her the entire time. After she left, I locked up the gym and went home around 4:15 PM. I didn't hear any music, and I certainly didn't see anyone touch the mascot locker. It was locked when I left."
Key Detail:
With Maya from 3:45-4:05 PM
Conflict:
Claims no music was playing
Witness Statement #3: Maya Chen
"I was really busy on Friday. I spent my entire afternoon in the darkroom developing film for the yearbook. I went in there at 3:15 PM and didn't come out until 4:45 PM. I was completely alone the whole time—developing film requires total darkness, you know. I didn't see Coach Henderson or anyone else after school ended. If someone stole the mascot, I wouldn't have seen it from the darkroom."
Key Detail:
In darkroom from 3:15-4:45 PM
Conflict:
Claims she was alone all afternoon
Detective's Reliability Log
1. Identify the CONTRADICTION. Which two witnesses have stories that do not match? Explain why.
2. Who do you think is being LESS reliable? Why? Use the "Perspective" or "Consistency" rule from your slides.
3. Inference Check: Principal Miller heard music, but Coach Henderson said there was no music. What might this suggest about what was happening in the gym?
Detective Briefing Guide Detective Briefing Guide
Lesson 1: Assessing Reliability
TEACHER ONLY
Objective
Students will evaluate the reliability of three different witness statements by identifying factual contradictions and assessing the speaker's perspective.
Key Skills
Identifying contradictions
Evaluating source credibility
Synthesizing multiple perspectives
The Secret "Truth" for Teachers
01
The Major Contradiction:
Coach Henderson claims Maya Chen was with him in the gym at 3:45 PM. However, Maya Chen claims she was alone in the darkroom from 3:15 PM to 4:45 PM. Both stories cannot be true.
02
The Sound Evidence:
Principal Miller heard loud music coming from the gym at 4:00 PM. Coach Henderson claims there was no music. This suggests Coach Henderson is either lying or trying to cover up what was actually happening in the gym.
03
Inference Preview:
Spoilers for Lesson 2: The loud music was actually used to cover up the sound of someone breaking into the storage locker or dragging a large mascot suit across the floor.
Facilitation Prompts
"Look at the times mentioned..."
Encourage ELLs to highlight every time/duration mentioned in the text (3:30, 3:45, etc.) to see where the overlap occurs.
"Why might Maya lie?"
Ask students if they've ever pretended to be busy to avoid helping someone. Does she have a motive to be 'unseen'?
ELL Scaffolding Tip
Use a T-Chart on the board. On one side, write "Coach Henderson says..." and on the other "Maya Chen says...". Have students come up and fill in what they see for 3:45 PM. The visual clash of "In the Gym" vs. "In the Darkroom" makes the contradiction concrete.
Physical Evidence Slides Lesson 02
Paper Trails
Cross-Referencing Physical Evidence
Evidence Collection Unit
Functional Evidence
Reading between the lines of "everyday" items.
Receipts & Tickets
Tell us WHERE and WHEN a suspect was active.
Maps & Blueprints
Tell us how FAR a suspect had to travel.
Schedules
Tell us IF their alibi is even possible.
Detectives don't just read stories.
The "Alibi Check" Method
Step 1
Read the Witness Statement to find their "Story."
Step 2
Check the Physical Evidence to find the "Facts."
Step 3
Do they MATCH or CLASH?
Physical Evidence
Incoming File: Folder 02
School Map
Bus Receipt
Coffee Shop Tab
"A receipt never lies, but a suspect often does."
— Chief Detective's Handbook
Analyze Now
Evidence Locker Packet Evidence Locker #02
R.M.S. Investigation Unit | Tag: Physical_Docs_01
Status Verified Evidence
Item A: Riverside Middle School Floor Plan
RM 101 Principal's
HALLWAY
RM 103 Darkroom
NORTH EXIT
MAIN CORRIDOR
"The Daily Grind"
CRIME SCENE Gym & Storage Locker
EQUIPMENT
SOUTH EXIT
WALKING TIMES:
Gym → Office: 3 min
Gym → Darkroom: 2 min
Gym → Coffee Shop: 8 min
Item B: Receipt
The Daily Grind
Riverside, CA
------------------
Date: Fri, Jan 16
Time: 03:55 PM
------------------
1x Black Coffee $3.50
1x Glazed Donut $1.25
------------------
Total: $4.75
Thank you! Come again.
Item C: Bus Pass
CITY TRANSIT
One-Way Passenger
Route 14B
Riverside High
Validation Time:
04:50 PM
Ticket #88219-X
IMPORTANT INVESTIGATOR NOTES:
Coffee Shop "The Daily Grind" is located just off-campus, an 8-minute walk from the Gym.
The City Transit bus stop is located outside the North Exit, a 1-minute walk from the Darkroom.
Witness statements from Folder #01 should be used to verify these alibis.
Alibi Checker Worksheet Alibi Verification Log
Operation: Paper Trail | Unit 02
Investigator: ___________________
Mission Instructions:
Compare the Witness Statements (Folder #01) with the Physical Evidence (Folder #02). Look for times and locations that do not match. If a suspect's story clashes with a fact, mark it as "BUSTED."
Suspect: Coach Henderson ID: RMS-002
His Story (Statement #1):
"I was in the gym from 3:45 PM until 4:15 PM organizing equipment."
Physical Fact (Item B):
Receipt from "The Daily Grind" at 03:55 PM.
Analysis:
Does the receipt match his story? Why or why not? (Check the map for travel time!)
VERIFIED
BUSTED
Suspect: Maya Chen ID: RMS-003
Her Story (Statement #3):
"I stayed in the darkroom until 4:45 PM. I didn't leave until then."
Physical Fact (Item C):
Bus Ticket validated at North Exit at 04:50 PM.
Analysis:
Does the bus ticket match her story? Is it possible for her to catch that bus? (Check the map!)
VERIFIED
BUSTED
Final Conclusion for Folder #02
Based on the Physical Evidence , which witness is most likely lying about their location on Friday afternoon? Support your answer with one piece of evidence (a time, a place, or a receipt).
Remember: Just because someone is lying doesn't automatically mean they stole the mascot... but it's a very big clue!
Reading Between the Lines Slides Lesson 03
Hidden Messages
Inferring Motive and Analyzing Tone
Digital Forensics Team
Reading Between the Lines
Subtext: The meaning that is not said directly.
What they said:
"Oh, I'm sure the Principal's plan will work out perfectly. It always does."
What they meant (The Tone):
Sarcasm / Jealousy
The speaker doesn't actually like the Principal or her plan.
Tone
The speaker's attitude toward the subject.
Motive
The REASON why someone might do something.
The "Motive Hunt" Checklist
Grudges
Is the person angry or upset with someone else?
Ambition
Do they want something they don't have?
Pressure
Are they afraid of getting in trouble?
In Lesson 03, we scan private emails to find the Hidden Why.
Suspect Correspondence Packet Intercepted Correspondence
Folder #03 | Focus: Tone & Motive Analysis
SECURITY LEVEL: DELTA-3
From: Principal Miller (pmiller@riverside.edu )
To: Coach Henderson (jhenderson@riverside.edu )
Date: Thursday, Jan 15, 08:30 AM
Subject: RE: Equipment Budget Request
Coach Henderson,
As I stated in our meeting, the school board has denied your request for new football helmets. We simply do not have the funds this year. I have also decided to redirect the "Mascot Maintenance" fund to pay for the new library computers. Since nobody seems to care about that old, smelly rat suit anyway, it shouldn't be a problem.
Please try to be a team player for once.
Regards,
From: Coach Henderson (jhenderson@riverside.edu )
To: pmiller@riverside.edu
Date: Thursday, Jan 15, 02:15 PM
Subject: RE: RE: Equipment Budget Request
Miller,
I hear you loud and clear. It’s funny how the football team is expected to win every game, but we can't even get safe gear. And taking the mascot money? That's just low. Rusty is the soul of this school, even if you think he's just "smelly."
Don't be surprised if the school spirit "disappears" along with the budget.
Henderson
Note found in Darkroom trash:
Hey Leo,
The "Mascot Makeover" project is a GO. I need that suit for the photoshoot on Friday afternoon. If I can't get permission, I'll just have to "borrow" it for a few hours. The darkroom is the perfect place to hide it because nobody ever comes in here but me.
Don't tell anyone, or the yearbook surprise is ruined!
- M.
Detective's Insight:
Look at the word "disappears" in Henderson's email. Look at the word "borrow" in Maya's note. How do these words reveal different motives for taking the mascot?
Motive Map Organizer Motive Mapping Tool
File #03-B | Subject: The Hidden Why
Name: ___________________
What is a Motive?
A motive is the reason why someone does something. In a mystery, everyone has a story, but not everyone has a reason to commit the crime. Use the correspondence (emails and notes) to find the motive for each suspect.
Principal
Evidence (Words/Tone)
"Nobody seems to care about that old, smelly rat suit..."
Inferred Motive (Why take it?)
Coach
Evidence (Words/Tone)
"Don't be surprised if the school spirit 'disappears'..."
Inferred Motive (Why take it?)
Maya
Evidence (Words/Tone)
"I'll just have to 'borrow' it... photoshoot... secret."
Inferred Motive (Why take it?)
The "Tone" Conclusion
Compare the TONE of Coach Henderson’s email to the TONE of Maya’s note. Which person sounds angry ? Which person sounds excited ? Explain how their tone helps you decide who is more likely to commit a "crime" vs. a "prank."
Piecing It Together Slides Lesson 04
The Timeline
Synthesizing Events & Sequence
Chronology Analysis Division
The "When" is the "How"
Connecting the dots across time.
Establishing a Baseline
What was the LAST time the mascot was seen? This is our starting point.
Finding the Gap
When was the locker UNATTENDED? This is the window of opportunity.
"If the timeline doesn't make sense,
Today's Detective Workshop
Categorize
Sort your evidence: Witness Stories vs. Physical Proof.
Synthesize
Place them on the Master Timeline to see where they clash.
Clue: The Loud Music is the Key!
Case Timeline Builder Master Timeline Reconstruction
Case #2026-001 | Level: Synthesis
PHASE 04: CHRONOLOGY
Detective Challenge: Below are "Clue Cards" gathered from folders #01, #02, and #03. Your job is to place them in the correct chronological order on the Master Timeline. Some events clash—make sure you identify where the Lies happen!
3:15 PM
Confirmed Action
Maya Chen enters the darkroom to develop film.
3:30 PM
Last Seen Sight
Write who saw the mascot here
3:45 PM
Suspect Claim (Henderson)
"I am in the gym with Maya right now."
CONFLICT DETECTED: Maya is still in the darkroom!
3:55 PM
Receipt Log
Coach Henderson buys a coffee at "The Daily Grind."
4:00 PM
Audio Evidence
What does Principal Miller hear in the gym?
4:50 PM
Transit Log
Maya Chen boards Bus 14B.
The Investigation Gap
Look at 3:55 PM (Henderson is at the coffee shop) and 4:00 PM (Music starts playing in the gym). If Henderson isn't in the gym, who is playing the music? Why would they play loud music while stealing a mascot suit?
Teacher Note: The music hides the sound of dragging the heavy mascot suit across the wooden floor.
Presenting Your Case Slides Case Closed
Drawing Conclusions
Final Report Presentation
Chief Investigator Status
Your Final Mission
State Your Conclusion
Name the person responsible for the disappearance of Rusty the River-Rat.
Cite the Evidence
Prove it! You must use THREE pieces of evidence from your folders.
Report Checklist:
Reliability Analysis (Lesson 1)
Physical Proof (Lesson 2)
Motive & Tone (Lesson 3)
Timeline Logic (Lesson 4)
How to Cite Evidence
Step 1: The Claim
"I believe [Suspect Name] took the mascot..."
Step 2: The Proof
"...because in Folder #02, the receipt shows..."
Step 3: The Why
"This proves they were lying about their alibi."
"A detective without evidence is just a person with an opinion."
Case #2026-001 Resolved
Hand in your Final Report to the Chief of Police (Teacher).
SYNTHESIS: COMPLETE INFERENCE: MASTERED CASE: CLOSED
Final Case Report Template Official Case Report
Riverside Middle School Investigative Unit
Confidential
Lead Investigator: _________________________
Date of Filing: _____________________________
Case Number: 2026-001
Subject: Mascot Disappearance
Section I: Final Conclusion
After a thorough investigation of all witness statements, physical evidence, and digital correspondence, I have concluded that the primary suspect responsible for the disappearance of "Rusty the River-Rat" is:
Section II: Evidence and Reasoning
Support your conclusion with at least three specific pieces of evidence from the case files.
1
Contradiction / Reliability Check
2
Physical Evidence / Timeline Check
3
Motive / Tone Analysis
Section III: Reconstruction of Events
Briefly explain how and why the crime was committed, using your inferences about the loud music and the budget cuts.
REPORT ID: RMS-FINAL-2026
OFFICIAL SEAL
Mystery Master Key Mystery Master Key
Case #2026-001: The Missing Mascot | TEACHER ONLY
The Guilty Party: Coach Henderson
Coach Henderson stole the mascot suit on Friday afternoon between 4:00 PM and 4:15 PM. He did this to protest budget cuts and "teach the Principal a lesson" about school spirit.
The Alibi Breakdown
The Claim: Coach says he was in the gym from 3:45–4:15 with Maya.
The Reality: Maya was in the darkroom (Statement 3 & Bus Ticket). Coach was at the coffee shop at 3:55 (Receipt). He lied to create an alibi.
The Motive Check
Principal Miller: Thought the suit was "smelly" and redirecting funds. She wants it *gone* officially, but stealing it wouldn't help her get new computers.
Maya Chen: Wanted it for a photoshoot. She is a "Red Herring"—she intended to borrow it, but Coach stole it first.
Coach Henderson: Angry and bitter. His tone is aggressive. He specifically threatened that spirit would "disappear."
Final Report Rubric
Criterion Target (4 pts) Developing (2 pts) Claim Clearly names Coach Henderson as the suspect. Names Maya or Principal, or claim is unclear. Evidence Synthesis Cites 3+ specific pieces (Receipt, Email tone, Bus ticket). Cites 1-2 pieces, or evidence is vague. Inference Correctly explains the music/dragging connection. Mentions music but doesn't explain its purpose. Language Use Uses detective vocabulary (alibi, motive, evidence). Uses simple language; vocabulary is missing.
"The mystery works best when students 'catch' the coffee receipt lie themselves during Lesson 2."
