The Detective’s DeskMEDIUM · CASE FILE
Medium · A museum desk after a tour
An access key disappears after a tour. A visitor returns a similar souvenir, while the guide says the genuine key never moved. Establish which object is which and whose account fails.
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.
The building is closed before any person leaves the grounds. The reception camera shows the desk and the guide lockers can be searched with the duty officer present.
Museum guide
The brass key stayed on the desk until I left. I only picked up my guide folder.
The key has a split ring. Similar souvenir keys have solid rings.
Visitor
I returned a solid-ring souvenir key after the tour. I was accused because it looked similar.
The souvenir shop receipt names the solid-ring version.
Reception clerk
I saw Sami leave carrying a green folder. I did not see inside it.
A desk photograph taken before the tour shows the split-ring key on a yellow tray.
Read each record on its own terms. A claim made by a person is different from a fact established by an independent record.
Physical record · Reception desk
Sami places his open green guide folder over the tray. As he lifts it, the split-ring key is visible caught inside its inner pocket. The tray is then empty.
Physical record · Guide lockers
The green folder is found in Sami’s locker with the split-ring access key in the same inner pocket. The supervised search records the recovery.
Physical record · Reception desk
Ada’s key has a solid ring and matches her souvenir receipt. It cannot be the split-ring access key in the earlier desk image.
Physical record · Reception desk
The genuine access key lies on a yellow tray and has a split ring. The solid-ring souvenir is not visible on that tray.
Physical record · Reception desk
Ruth’s reception log records a green folder leaving. It explicitly says its contents were not checked. Her record is not proof that the folder was empty.
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.
Compare the records with each account. Work out what the evidence establishes, then separate that finding from anything it does not prove.