Pet the cat, either as Cleo or Guy.

Look through the telescope during the daytime.

Get more than 50% of answers wrong explaining the case (on hard mode).

Find 40 doggy bags and get the ending reward.

Complete the side-quest to find the communion cup and get the ending reward.

Find a hidden clue that reveals the truth about the opening scene ghost sighting.

Read all 3 historical society books in the library.

Find the statue of Elias Abel on Gallows Point.

Capture the culprit by catching them in the act.

Get caught by the "ghost" chasing after you.