Athough it was not used in the film, it helps to know that the young Santino witnessed the murder.

It is not deemed necessary for the film to work, and this is but one of the differences between film and novel. It is not hugely important, but it is interesting.

I was just thinking about the "bada-BING!" when it occurred to me, that this is why he is so enthusiastic when informing Michael of what it's like to blow someones brains out from 2 feet away...."you wanna do that? You wanna live that kinda life? Well let me tell ya kid, this is what I grew up with"... and bada-binging for other people too. Seemed to make sense.

(sorry below post an accident)