Approach everyone with smile in your face and murder in your heart.
Delf. A. Bryce. FBI Agent and amazing gunfighter.
Why would I use such an politically incorrect quote? Because you never know what lurks in the heart of a person you are about to meet as two people found out the hard way. They were just answering a job ad in Craiglist that turned out to be an invitation to attend their deaths.
It is good to see that in our so-called modern times, there are trusty people that believe in the goodness of their fellow human beings. I am not one of them.