
Well, it's really extreamly hard if u are not already being choped up and eaten alive... Watch the movies, Last house on the left, Ed Gane, Fried Green Tomatoes, Helter Scelter, only the first Friday the 13th and Copy Cat... These movies will prep u on the type of personalities that u should be awair of...
Now that being said, u could know someone and will never have a clue becouse they are content with their psyconess and have control over the urges of insanity.
Not to worry... Micro expressions are your savior, and some sly covert social manipulation. By dropping questions, hints on siduatuons and obscure inuendos that have no "red flag" indicators to anybody, just by observing their facial, behavioral, body and voice sound responces, along side there verbal reactions u can immeadietly tell within a few hours max, if you should be running to the hills... Unless ofcourse you are alone with them in the hills, then ur pretty much lunch meat...
Have fun campers! ;)

