A lot of people won’t believe this but …  within about 7-10 feet, a knife can be more dangerous than a firearm.  So be careful if someone approaches you with a knife in their hand.  For  some reason many people don’t realize how dangerous a knife can be up close, I don’t know why.

Generally, therefore, if I am not sure about a person I won’t let them get within 7-10 feet as a result.