This achievement is on Case 5 and it is MISSABLE.
You need to do two things for this achievement. First, you need to analyze the binder which is found in Gleason Family Self-Storage. To do this use the document analysis computer and move the three sliders so they show the most text. Second, you need to find the hard drive which is found in the Apiary, Beatriz Salazer's Hideout. All you need to do then is run a computer analysis on it. It is essential you do this before you talk to Beatriz and say "Jim get her out of here" as this will end the case.
For a walkthrough of this case and a guaranteed way of getting this achievement please use this: walkthrough (Thanks to Yelll o for this great walkthrough)