“What to do” scenario

So I am pretty solid of defending myself. My question is what if I witness a crime happening? Scenario: I am in the back of a store. A guy comes in said store and pulls a gun on the clerk and starts robbing the place. He doesn’t see me, doesn’t know I am there but I am witnessing this all happen in front of me. Do I have a right to defend others or should I just stay out of it, stay low and out of sight? I am guessing if he starts executing people, he will eventually get to me and my family so right or wrong, I will put them down at that time. My question is if he is just robbing the place and leaving…. Thoughts?Fairly new to conceal carrying. Not looking to be a vigilante or anything, just want to be a law abiding citizen. via /r/CCW https://ift.tt/3ddQup9