Usually an armed robber would not choose a wal-mart parking lot to rob someone with cameras and a steady steam of witness.
I don't give beggars money but I have talked to a few. Some of them had interesting stories, some where worthless trash, some were crazy.
-One guy that used to beg in a town I lived in grew up there worked 2 jobs and one day his wife stepped out in front of a bus and it killed her he lost his marbles and ended up on the streets
(I heard the story from people that grew up with him).
-A couple I talked to were skizo crazy too crazy to apply for help so they were just stuck in an endless survival cycle of begging and surviving.
-A couple were savage alcoholics trying to stay drunk.
Just because someone is homeless or a beggar doesn't mean they are a savage zombie that needs to be held at gun point. Keep walking and ignore them, Just part of life in the city.