The Detective’s DeskOren Bell
Recorded packet handler
“Establish my packet, location and event from the verified custody record.”
HARD · CASE FILE
The valid seal from the wrong batch
Hard · NORTHBRIDGE SEAL OFFICE
A seal can have a mathematically valid serial and still belong to a withdrawn batch. The target must satisfy both the calculation and the date rule. The archive retained the competing reconstructions in separate packets. Rebuild their custody events, identify the proposal supported by the analytical records, then name that packet’s recorded handler. The packet events form a separate ordered register; do not substitute a calculated clock time for a review-slot label.
Read the case file below, or open the interactive desk to examine records, keep notes and submit your reasoning. These are the case materials, without the solution.
Your assignment
Who handled the packet containing the supported reconstruction?
- The analytical records answer the analytical question; worksheet records establish the packet custody reconstruction. Candidate proposals and supplementary recollections are claims to test.
- There are 4 ordered events. Use each listed person, location and item once in its column. “A immediately before B” means A is in the row directly above B, with no row between them.
- 6 verified records support the complete submission. Keep the separate context note out of the proof.
- No outside facts or unstated exceptions are required. The complete board and report are assessed together.
People and accounts
Lena Ford
Recorded packet handler
“Establish my packet, location and event from the verified custody record.”
Pera Dean
Recorded packet handler
“Establish my packet, location and event from the verified custody record.”
Tavi Cole
Recorded packet handler
“Establish my packet, location and event from the verified custody record.”
Case records
Read each record on its own terms. A claim made by a person is different from a fact established by an independent record.
VERIFIED RECORD C
Submitted seals
A: code 1234, batch S. B: code 2340, batch R. C: code 3457, batch S. D: code 4562, batch T. All are proposed for use on 18 June.
Combine each code with its own recorded batch.
CONTEXT NOTE
Seal ink
Every submission uses red ink. Ink colour is not part of the serial or batch rule.
This describes the setting; it does not establish the requested result.
VERIFIED RECORD A
Serial formula
For four-digit code abcd, d must equal (a + 2b + 3c) modulo 10. Codes keep any leading zero. No other checksum rule applies.
Calculate each check digit independently.
VERIFIED RECORD B
Batch ledger
Batch R was valid through 17 June only. Batch S is valid from 18 through 20 June inclusive. Batch T starts on 19 June.
Check validity for the precise use date, 18 June.
RECONSTRUCTION RECORD
Packet proposal index
This is the same investigation’s packet custody record. There are 4 ordered events, labelled Review 1, Review 2, Review 3, Review 4. Each listed person, location and item occurs exactly once. These slots describe record order, not times from the analytical problem. Each packet contains the proposed reconstruction shown in the index. Solve the original three analytical records to identify the supported proposal, then trace its packet to its handler. Control packets have no proposal and cannot be the target.
- The event handled by Pera Dean occupies slot 4 (Review 4).
- The event handled by Lena Ford and the event at Review bench are exactly 3 positions apart, with 2 intervening events; this alone gives no direction.
- The event at Intake counter and the event at Reading desk are exactly 2 positions apart, with 1 intervening event; this alone gives no direction.
| Packet | Proposed analytical answer |
|---|---|
| Packet Amber | Seal D |
| Packet Birch | Seal A |
| Packet Cedar | Seal B |
| Packet Dune | Seal C |
Use each column’s choices exactly once. Verified relationships govern the board; proposed answers and later recollections do not override them.
RECONSTRUCTION RECORD
Custody sequence
The relationships below were verified independently. “A immediately before B” means A is in the row directly above B, with no row between them. Keep relationships from all worksheet sources together.
- The event at Reading desk occupies slot 1 (Review 1).
- The event at Review bench and the event involving “Packet Dune” are exactly 3 positions apart, with 2 intervening events; this alone gives no direction.
Use each column’s choices exactly once. Verified relationships govern the board; proposed answers and later recollections do not override them.
RECONSTRUCTION RECORD
Cross-check and accounts
The relationships below were verified independently. “A immediately before B” means A is in the row directly above B, with no row between them. Keep relationships from all worksheet sources together.
- The event handled by Oren Bell is the same event as the event involving “Packet Amber”.
- The event handled by Oren Bell and the event involving “Packet Birch” are exactly 2 positions apart, with 1 intervening event; this alone gives no direction.
Use each column’s choices exactly once. Verified relationships govern the board; proposed answers and later recollections do not override them.
Questions to resolve
Which submitted seal was valid for use on 18 June?
Match every recorded item to its handler or reviewer.
- Packet Dune
- Packet Amber
- Packet Cedar
- Packet Birch
At which recorded event was the target packet handled?
Use the interactive case desk to select your finding and cite the records that support it. The answer is checked there, and your progress stays in your browser.
Build your finding
Compare the records with each account. Work out what the evidence establishes, then separate that finding from anything it does not prove.