CASE 002
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THE CASE OF THE IMPOSSIBLE SUSPECT
Three minutes. That is all it took. A masked figure walked into the bank and walked out with $86,000. By the time police arrived, the robber had vanished. The cameras had seen everything. Or so investigators thought — until they realized the cameras had been lying to them all along. Can physics reveal why?
CASE BRIEFING
At 4:47 PM on a Friday, a masked figure walked into Riverside Community Bank, handed a note to the teller, and walked out three minutes later carrying $86,000 in a canvas bag.
No weapon was displayed. No one was hurt.
By the time the first officer arrived, the robber was gone.
The cameras had recorded everything. Investigators reviewed the footage within the hour — and within two hours they had a name.
Daniel Mercer.
He was 6 feet 2 inches tall. The security footage appeared to show a robber of almost exactly that height. His dark jacket matched witness descriptions. He had no alibi for the time of the robbery. And three months earlier he had closed a business account at Riverside Community Bank following a bitter dispute with the branch manager over unauthorized fees — a dispute that had ended with Daniel threatening to make the bank "pay one way or another."
By the following morning Daniel had been arrested.
He had a physiotherapy appointment scheduled for Monday. A job interview on Wednesday. A dispute with the bank still unresolved in the courts.
When investigators told him why he was being held, he looked down at the support boot on his ankle — he had torn a ligament three weeks earlier — and said something that stopped the lead investigator mid-sentence.
"I was at my physiotherapy appointment at 4:30. I have a receipt. I have a witness. And I can barely walk to my car, let alone run out of a bank."
The investigators exchanged a glance.
They had not yet considered the running.
Your investigation begins now.
The cameras captured the robbery, the escape, and the getaway. But cameras do not always show what investigators assume they show.
Examine all five Evidence Files. Pay close attention to how measurements were taken — not just what they produced. Some evidence will appear to confirm everything investigators already believe. Some will quietly take it apart.
Can physics reveal what the cameras actually recorded — and who was really behind the mask?
Instructions:
Play solo or with a team of up to 5 investigators. Examine the five Evidence Files together, or divide them among your team and have each investigator analyze different clues. Share what you discover, compare theories, and decide which evidence matters most.
When you've examined all the evidence, work individually or as a team to reach your final verdict—then reveal the solution to see if you cracked the case.
EVIDENCE FILES
EVIDENCE FILE 01 +
EVIDENCE FILE 01 — SECURITY CAMERA ANALYSIS
Case Reference: RCB-2024-0919
Location: Riverside Community Bank — Main Lobby
Camera: Lobby Camera 03
Date: Friday
Time: 4:48 PM
WHAT THE FOOTAGE SHOWS
Security footage captured the masked robber entering through the main lobby doors of Riverside Community Bank.
Investigators used a sign board visible in the same frame to estimate the robber's height.
Bank records confirm the sign is exactly 72 inches — 6 feet — tall.
Using the sign as a reference, investigators estimated the robber's height at approximately 6 ft 2 in — 188 cm.
That immediately focused the investigation on Daniel Mercer — also 6 ft 2 in tall.
ONE DETAIL BURIED IN THE MEASUREMENT NOTES
The investigation report recorded two distances almost as an afterthought.
The robber was standing approximately 8 feet from the camera.
The information sign was approximately 14 feet from the camera.
In the image they appeared almost side by side. In the actual room they were nearly 6 feet apart.
No one on the investigation team flagged this at the time.
A BRIEF NOTE ON CAMERA PERSPECTIVE
A camera compresses three-dimensional space onto a flat image. Objects closer to the lens appear larger than objects of the same size further away — the same reason a lamppost near you appears taller than a building in the distance.
When investigators compare the height of two objects in the same camera frame they are assuming both objects are at the same distance from the lens.
The robber and the sign were not at the same distance.
The 6 ft 2 in figure was built on a flawed assumption — and an innocent man was arrested because of it.
YOUR TASK
The robber appeared to be the same height as a 72-inch sign.
But the robber was 8 feet from the camera. The sign was 14 feet away.
Does this affect the height estimate? If an object closer to the camera appears larger than it actually is relative to objects further away — what does that tell you about the 6 ft 2 in figure? Was the robber taller or shorter than that estimate suggests?
Research how camera perspective affects apparent size. Then consider whether the 6 ft 2 in height estimate should be trusted — or revised.
EVIDENCE FILE 02 +
EVIDENCE FILE 02 — SIDE EXIT CAMERA ANALYSIS
Case Reference: RCB-2024-0919
Location: Riverside Community Bank — Side Exit
Camera: Exterior Camera 07
Date: Friday
Time: 4:50 PM
WHAT THE FOOTAGE SHOWS
Two minutes after the lobby footage, a second camera captured the masked robber leaving through the bank's side exit — carrying the bag.
This time investigators had a different reference point for estimating height.
Bank construction records confirm the doorway is exactly 7 ft 0 in — 213 cm — tall.
Unlike the lobby footage — where the robber and the reference object were at different distances from the camera — the robber was passing directly through the doorway when the image was captured.
The robber and the doorframe were at approximately the same distance from the camera.
Using the doorframe as a reference, investigators calculated the robber's height at approximately 5 ft 9 in — 175 cm.
THE PROBLEM
Two cameras. One robber. Two different heights.
6 ft 2 in from the lobby camera.
5 ft 9 in from the side exit camera.
A difference of five inches.
The same person cannot actually be two different heights.
One of these measurements is more reliable than the other.
YOUR TASK
Think carefully about how each measurement was made.
In Evidence File 01 — the robber and the reference sign were at different distances from the camera. In this file — the robber and the reference doorframe were at approximately the same distance.
Which measurement do you trust — and why? What does the more reliable estimate tell you about whether Daniel Mercer — 6 ft 2 in — could be the robber?
Research how height estimation from security footage works and what conditions produce accurate results. Then consider what the five-inch discrepancy between the two cameras is actually telling you.
EVIDENCE FILE 03 +
EVIDENCE FILE 03 — ESCAPE ROUTE ANALYSIS
Case Reference: RCB-2024-0919
Location: Rear Parking Lot — Riverside Community Bank
Camera: Parking Camera 02
Date: Friday
Time: 4:51 PM
WHAT THE FOOTAGE SHOWS
After leaving through the side exit, the robber crossed the rear parking lot at speed.
Two light poles along the escape route provided investigators with a precise measurement opportunity.
Facility maintenance records confirm the poles are exactly 30 meters apart.
Camera timestamps show the robber passing the first pole at 4:51:08 PM and the second pole at 4:51:13 PM.
30 meters in 5 seconds.
THE CALCULATION
Using the formula:
Speed = Distance ÷ Time
30 m ÷ 5 s = 6 m/s
That is approximately 13.4 mph — 21.6 km/h.
The physics had just produced a second piece of evidence — and this one was as precise as the first was flawed.
The average recreational runner moves at approximately 8 to 10 mph. This person was moving at 13.4 mph — faster than most people can sprint — while carrying a bag containing $86,000, on a wet parking lot surface, and according to a witness nearly lost their footing changing direction.
Whatever the cameras got wrong about height — they got this right. And this number ruled out Daniel Mercer as completely as any courtroom verdict could.
DANIEL MERCER — RELEVANT DETAIL
Three weeks before the robbery Daniel Mercer suffered a serious ankle ligament tear.
At the time of the robbery he was still wearing a support boot and had been medically instructed to avoid running while the injury healed.
At his physiotherapy appointment at 4:30 PM — seventeen minutes before the robbery began — his therapist recorded his mobility as severely restricted.
YOUR TASK
The escape footage has given investigators a measurable physical characteristic of the robber — running speed.
Daniel Mercer told investigators he was at physiotherapy at 4:30 PM and could barely walk to his car.
His therapist's record supports that claim.
Can a person medically restricted from running cover 30 meters in 5 seconds while carrying a bag? Does this evidence support or contradict the case against Daniel Mercer?
Research average human running speeds and what a serious ankle ligament injury does to mobility. Consider what the physics is telling you — and whether the original prime suspect is still a credible one.
EVIDENCE FILE 04 +
EVIDENCE FILE 04 — SUSPECT PROFILES
Case Reference: RCB-2024-0919
Investigation: Riverside Community Bank Robbery
Prepared By: Detective S. Okafor
Date: Friday — 7:30 PM
BACKGROUND
Following the camera analysis and escape route measurements, investigators expanded their search beyond Daniel Mercer.
The physical evidence established that the robber was:
Approximately 5 ft 9 in — 175 cm tall
Capable of running at approximately 6 m/s — 13.4 mph
Moving freely — no apparent mobility limitation
Three individuals came under scrutiny.
DANIEL MERCER
Height: 6 ft 2 in — 188 cm
Vehicle: Dark-gray sedan
Physical condition: Torn ankle ligament — support boot — medically restricted from running
Daniel was the original prime suspect.
His height does not match the more reliable camera estimate.
His physical condition at the time of the robbery is inconsistent with the escape footage.
His physiotherapy receipt and therapist's record place him at an appointment seventeen minutes before the robbery began.
JASON COLE
Height: 5 ft 9 in — 175 cm
Vehicle: White pickup truck
Physical condition: Regular recreational runner — no known limitations
Jason's height matches the side exit camera estimate precisely.
His running ability is consistent with the escape footage.
Investigators confirmed Jason had visited Riverside Community Bank as a customer earlier that same afternoon.
ERIC LAWSON
Height: 5 ft 9 in — 175 cm
Vehicle: Black SUV
Physical condition: No known mobility limitations
Eric's height also matches the side exit camera estimate.
Nothing in his profile contradicts the physical evidence from the escape footage.
A parking attendant at the business adjacent to the bank recalled seeing a black SUV park in the side street behind the bank approximately 20 minutes before the robbery. The driver sat in the vehicle without entering any nearby business. The attendant could not identify the driver.
YOUR TASK
Daniel Mercer's height and physical condition no longer fit the evidence.
Two suspects remain consistent with the physical profile — Jason Cole and Eric Lawson.
What additional evidence would you need to distinguish between them? Which detail about Eric stands out — and why might a driver sit in a vehicle for 20 minutes outside a bank without entering?
Consider what you have established so far and what Evidence File 05 might reveal.
EVIDENCE FILE 05 +
EVIDENCE FILE 05 — THE DROPPED PHONE AND GETAWAY VEHICLE
Case Reference: RCB-2024-0919
Location: Rear Parking Lot — Riverside Community Bank
Recovered: Friday — 4:53 PM
Prepared By: Detective S. Okafor
PART ONE — THE DROPPED PHONE
Investigators searching the rear parking lot discovered a smartphone lying near the second light pole — directly along the robber's escape route.
The screen was cracked. The phone had struck the pavement.
The registered owner: Jason Cole — Suspect B
For investigators this appeared to change everything.
Jason was 5 ft 9 in. He was a regular runner. And now his phone was lying at the exact point where the robber had been recorded passing at 4:51:13 PM.
It looked like the strongest piece of evidence in the case.
Investigators prepared to make an arrest.
Then they checked one more thing.
THE TIMESTAMP THAT CHANGED EVERYTHING
Records from a coffee shop two blocks away showed Jason Cole making a card payment at 4:49:36 PM — while the robbery was still in progress inside the bank.
The robber appeared on lobby camera at 4:48 PM.
The robber left through the side exit at 4:50 PM.
Jason's payment was recorded at 4:49:36 PM.
Jason could not have been inside Riverside Community Bank and standing at a coffee shop counter at the same time.
So why was his phone beside the escape route?
EARLIER FOOTAGE — THE EXPLANATION
Investigators reviewed footage from earlier in the afternoon.
At 3:38 PM — more than an hour before the robbery — Jason Cole had visited the bank as a regular customer.
As he walked along the rear walkway after leaving, a camera captured a small dark object falling from his jacket pocket.
Jason did not notice. He kept walking.
The phone had been lying there before the robbery began.
The clue that appeared to identify the robber had nothing to do with the robbery at all.
PART TWO — THE GETAWAY VEHICLE
After passing the second light pole at 4:51:13 PM the robber continued toward the far end of the parking lot.
A camera positioned at the lot exit captured the robber approaching a vehicle and getting in.
The vehicle pulled away immediately.
The footage was not sharp enough to read the license plate or identify the driver.
But the vehicle's size, shape, and colour were identifiable, and it showed a distinctive red-and-white mountain-shaped sticker on its rear windshield.
It was a black SUV.
CONNECTING THE EVIDENCE
Investigators returned to what they knew about the black SUV seen by the parking attendant before the robbery.
The attendant had noticed it because the driver sat inside without entering any nearby business — for approximately 20 minutes before the robbery began.
A driver waiting in a vehicle for 20 minutes. Positioned on the side street behind the bank. Leaving immediately after the robbery ended.
And now a black SUV recorded at the parking lot exit at the moment the robber reached a vehicle and got in.
Of the three persons of interest:
Daniel Mercer drove a dark-gray sedan
Jason Cole drove a white pickup truck
Eric Lawson drove a black SUV
YOUR TASK
You now have all five Evidence Files.
Jason Cole's phone looked like the most damning piece of evidence in the investigation — until the timestamp proved it had been there for over an hour before the robbery began.
The getaway vehicle tells a different story.
Using evidence from all five files — who robbed Riverside Community Bank? Build your case using the physics, the timeline, and the vehicle evidence. Which clues were genuine — and which became something else entirely when you examined them carefully?
HAVE YOU SOLVED THE CASE?
Review the evidence and decide what you think happened. If you're investigating with others, discuss your findings and agree on your final verdict before revealing the answer.
Once your team has reached a conclusion, reveal the answer.