The Sunburst Medallion Theft Investigation

This case involves the theft of the valuable "Sunburst Medallion" from a secure display case at the city museum. The incident occurred on the night of October 12th, between the museum's closing at 10:00 PM and the night guard's final check at 1:00 AM. Three former museum employees – Anjali (ex-curator), Bharat (ex-security expert), and Chitra (ex-exhibits designer) – are the primary suspects.

Theft Details: Time Window and Entry Method

The theft took place during a specific timeframe:

• Museum closing: 10:00 PM
• Guard's final round: 1:00 AM
• Medallion confirmed present: 10:30 PM

Crucially, the investigation revealed that the display case was accessed using a specific five-digit security code. The established facts state that only Anjali and the museum director knew this code.

Suspect Profiles and Alibis

Let's examine each suspect's situation:

Anjali (Former Curator)

• Known to know the five-digit security code.
• A unique silver button, similar to those on her coat, was found near the display case.
• No specific alibi is provided, but her knowledge of the code is a significant factor.

Bharat (Former Security Expert)

• Alibi: Attended a distant relative's birthday party from 8:00 PM to 1:30 AM, confirmed by multiple witnesses.
• Boasted about disabling magnetic locks remotely, but the log indicates the code was used, not a remote override. His alibi covers the entire theft window.

Chitra (Former Exhibits Designer)

• Alibi: Working late at a graphic design studio.
• Entered the studio at 7:00 PM and exited at 11:45 PM.
• The studio is a 20-minute drive from the museum.

Analyzing Conditions for Chitra's Guilt

To determine a necessary condition for Chitra to have stolen the medallion, we must consider the facts related to her and the theft itself. The key piece of evidence is how the display case was opened: using a five-digit code known only to Anjali and the director.

Evaluating Each Option:

• Option 1: She must know the five digit code

  The security logs explicitly state the case was opened using a specific five-digit code. If Chitra is responsible for opening the case and stealing the medallion using this method, she absolutely must possess this code. Since the facts state only Anjali and the director knew it, this condition points towards her needing that knowledge or obtaining it from someone who knew it. Therefore, knowing the code is a direct requirement for her to have used the documented entry method.

• Option 2: She must have left the graphic design studio before 11.45 pm

  This statement contradicts the established facts, which clearly state she exited the studio at 11:45 PM. Therefore, it cannot be a necessary condition for her guilt.

• Option 3: The theft must have occurred after she left the studio and before 1 am

  Chitra left the studio at 11:45 PM. Allowing for a 20-minute drive, she could potentially arrive at the museum around 12:05 AM. The theft window closes at 1:00 AM. While this timing (12:05 AM to 1:00 AM) is *within* the potential window for Chitra to act, it is not a necessary condition *for her to have stolen it*. The theft could have occurred earlier (e.g., by Anjali at 11:00 PM), and Chitra might still be considered a suspect for other reasons, or she might be innocent. This option describes a possible timeframe for the theft if Chitra were involved, not a prerequisite for her guilt.

• Option 4: She must have worked with Anjali to disable the locks

  This is a plausible scenario if Chitra did not know the code herself. If she collaborated with Anjali, Anjali could have provided the code. However, it is not strictly a *necessary* condition for Chitra's guilt. The most direct necessity, based on the evidence of the code being used, is that *she* must have the means to open the case, which is the code itself. Working with Anjali is a *method* of acquiring or using the code if she doesn't possess it independently, but knowing the code is the fundamental requirement for operating the lock as described.

Conclusion on Necessary Condition

Given that the display case was opened using a specific five-digit code, and only Anjali and the museum director knew this code, any suspect who committed the theft via this method must have known the code. For Chitra to have stolen the medallion using the documented entry method, it is absolutely necessary that she knew the five-digit code.