Are the surveillance cameras clearly visible and the bystanders are aware of them? I wonder if the bystanders would react differently if they weren't aware that

Are the surveillance cameras clearly visible and the bystanders are aware of them? I wonder if the bystanders would react differently if they weren't aware that they are being recorded. Another thing I wonder is if they refuse to help then maybe they think there'll be repercussions like being ostracized when the footage goes public.