Unfortunately, honest people and Liars alike will both tell you that they are honest & trustworthy. The liars & cheats don't tell you upfront what they really are, so it IS hard to tell the difference. It would be better if it were tattooed on their foreheads! The best way I can think of to "test" a person of interest, is to just be friends with them a long while. I mean, "buddy" kind of friend. Check their integrity by seeing if they lie to your other mutual friends (maybe to get out of doing stuff with them or whatever), ask about their past relationships to see why they didn't work out. People are usually a little more honest with their confidante than they are someone they're romantically involved with. Then, if things check out and you're still interested, try to take it to the next level. Otherwise, you could go through the hassle of learning how to read body language or become a private investigator.