In total there are 77 Clue Locations in the game and collecting them all will unlock the following trophies.

'The Tale of The Two Sisters' Gold Trophy
Unlocked when the group find ALL the clues from the Twins Clueline.

'The Fateful Descent' Gold Trophy
Unlocked when the group find ALL the clues from the 1952 Clueline.

'You Opened Their Eyes' Gold Trophy
Unlocked when the group find ALL the clues from the Mystery Man Clueline.