Here is the trophy guide for A Mystery, Solved. This video guide was not made by me so all credits for the video go to XCVii007r1, he shows you where ALL of the letter scraps are. The best way of getting around to get these letter scraps is a helicopter (these can be collected by any of the 3 characters) once all 50 of these are collected switch over to Franklin (if you have not collected the letter scraps as him) as a strangers & freaks mission has opened up for him.... Go to it and deal with Dreyfuss. Once done the trophy will pop. good luck. if you need any help drop me a message :)