This achievement is Unlocked for Finishing Case 2 A study in Green
The only requirement is that you finish the case.
In total there should be 19 clues unlocked on the deduction screen. There are various deductions you can make and any will unlock the achievement.
The correct deduction is:
Its worth Replaying the endings with the incoreect deductions as they are entertaining although not needed for the achievement.
Incorrect deductions are: