This is a long thread and I just stumbled on this site. This sparked my membership and first post. I use to work undercover narcotics and when I dressed the part, I could see how I was treated by the general public. People tended to walked around me, stare at me, pull their children away from me. My family looked at me differrently, my kids didn't recognize me at times. I had a long beard, tats on my arms were always showing. One thing is for sure, when I dressed like this, I was never a vicitm, nobody ever wanted to have a confrontation with me. The real me is that I have three kids, a great wife, nice home, I'm religious, I live in the country, I love life. Now we wouldn't know any of this just by looking at me when I worked in Narco. I also use the appearence of people when working to help me cue into the criminal activity. But as other posters have said, that is only one helpful tool, it is the totality of many factors that turns your hunch into probability.