I know this will be coming way too late (response is 2 months old, but I just recieved the game a day ago.) But to use only 3, you need to click 3 locations, then the Search button becomes available. Fingerprinting is a total chore because one missed click and you mess up your 100% skill far too easily.
Phear my Uber Gimpyness!
RRoD #1: 9/27/08