There are many special achievements in "Shadows of Doubt", and connecting them all is one of them. The requirement to achieve this achievement is to pin 100 unique items to the clue board in a single game. Go on, just find something and order it for any case.
How to achieve the achievement of "All Evil Shadows and Suspicions"
All connected
Pin 100 unique items to the clue board in a single game
Place 100 different items in any case on the clue board, such as documents, emails, fingerprints, names, and anything not related to the case.