I've been at this for a few years but only in a situation where I'm doing my own screening for about a year. I've used all the conventional methods, but ultimately I rely on my gut. It's always served me well.
I recently had someone contact me for an appointment, I asked for references or if he was a member of a verification site. He replied that he was very private, gave me the address of his apartment and offered to take me out to dinner first. My Spidey sence started going off, why would a private person just give me their address? When I mapped it there was nothing but a warehouse, some trailers and a private house. I'm sure the house COULD have an apartment in it, but it just didn't feel rite.
The news has been talking about the escort that shot the serial killer a lot the past few days and all this got me thinking. Are their any other ways to know if the person your meeting is safe? I'm not too worried about LE but murderers, rapists etc.