Originally posted by waynethegame:
Actually, the movie DOES kind of hint that it was Luca.. there's a deleted scene (the same one where Hagen tells Vito about Woltz's little escapade with that 12-year old girl) where Vito says something like "Send Luca Brasi to me.. I think maybe we can reason with this Mr. Jack Woltz."
That's true, and that's why we infer that Luca either did the horse-hacking or arranged it. But the novel gives no hint at all of Luca's involvement. The novel does give several examples of the Don's power with the Hollywood movie industry labor unions, so we might infer that the horse execution was arranged via local thugs.