What is the best way to respond to really racially charged comments?

I had the unfortunate experience in my job recently to walk into a receiving department where I often make deliveries and walked up to 3 employees where the one whom I normally deal with was making incredibly blatant racial comments in regards to the election. So strong were his words that he was even talking about "shooting a N***** " if he even looked at him like he "owed him something". The other employees were baiting him and laughing and I really don't believe he was going to carry out any violence but I was so taken aback that I just left in disbelief that someone who I have actually dealt with for months and seemed so (ordinary) could be so filled with hatred. I guess since I was white too he did not think I would be offended or something. So now outside of him probably just dismissing me as a "N***** lover" or something if I called him on his comments what would you suggest I do? Contact authorities? (seems extreme, but the hatred was real) Contact this relatively small family owned company's management? Ask him directly what his hatred was about next time I see him? I know I cannot stand idle by and NOT address this as acceptable behavior, but I am not sure what would be the most affective action to bring about real change in an individual who was probably brought up on a doctrine of hate-- besides a possible reprimand from his superior may in turn simply fuel more hate. I was actually thinking of simply giving him the movie American History X. I don't know....any suggestions are gladly welcomed. Thanks!