For Detective Grimoire: Secret of the Swamp, in order for the game to allow you to complete it, you must go through all four conversation topics with every character, complete every character's challenge, and find all the clues necessary to complete the final presentation to Officer James. The following outlines the minimum requirements to be able to complete all of the above.
Conversation topics
The first two conversation topics — along with being able to talk to suspects in the first place — are unlocked by inspecting the outline of the body at the crime scene.
The third conversation topic requires deducing that the culprit used a Boggy costume, which requires the following to be performed:
- Obtain the photo of "Boggy" from Burle, acquired through performing the challenge for Burle (see next section)
- Find the costume design in the café trash can
The fourth conversation topic requires deducing that Richard Remington was part of a secret hunting society, which requires the following:
- Obtain the keys to the office, which happens automatically after unlocking the third conversation topic above
- Obtain the pitchfork in the office
- Inspect the shotgun in the office
- Reassemble the hunting photo in the office
Challenges
Burle's challenge is unlocked after ruminating on Van de Peer's claim of his absence last night, which requires performing the first two conversation topics with Van de Peer and introducing yourself to Burle.
Van de Peer's challenge is unlocked after deducing he only recently got permission to film in the swamp, which requires asking Burle about his job and introducing yourself to Van de Peer.
Agent Folder's challenge is unlocked after deducing the lock pick found at the crime scene might be his, which requires obtaining the lock pick from the crime scene (reed 3) and asking Folder about last night.
Harper's challenge is unlocked after deducing that Remington left the café feeling ill after Harper sold him a Bog Dog, which requires asking Burle about last night and asking Harper about his job.
Lady Weybridge's challenge is unlocked after deducing she was in the swamp when the explorer discovered the creature, which requires introducing yourself to Harper, obtaining the explorer's journal from the museum, then asking Weybridge about her "job" and presenting the journal to Weybridge.
Sally's challenge is unlocked after deducing her leggings are covered in the same slime as the murder weapon, which requires obtaining the pitchfork from the crime scene, asking Sally about last night (which acquires the leggings), then using Weybridge's chemistry set to analyze both the pitchfork and Sally's leggings (which requires asking Weybridge about her "job").
Echo's challenge is unlocked after ruminating on his spending more time in his tent than holding his protest sign, which requires presenting Echo's profile to Sally (which requires introducing yourself to Echo first) and asking Echo about his "job".
Necessary clues
Most of the clues necessary to complete the final presentation to Officer James are acquired by virtue of performing actions required to unlock conversations and challenges per the above, with one exception: the Boggy costume head must be collected from the gift shop wagon.
All the above accounts for the minimum required to complete the game.
