basically common sense.
if they don’t look like a gangsta thug and have a mean looking scowl on their face, calling you cracka and ‘kill the white girl!’ and that kind of stuff, you are probably okay.
it is when they burst into a store with masks on and the guns ready to use is when it’s a problem. walking in with them on their backs - like a regular’person - saying hi, smiling, getting a cart,and starting to shop - again like a normal person - your common sense is that they are not a hardened violent criminal.