Identity of the killer (spoilers)

I think nobody came up with this on the board: I think that the identity of the killer is hinted by two sentences at the beginning and at the end of the movie.
At the beginning a voice speaks to the young Truman: she says that his father gave him the billiard ball and instigated him to fight. The boy protects him, but it is his father who wants to initiate him to brutality.
In the end the killer asks Truman "do you understand who I am, now?", meaning that Truman should know him. He also says that he is "very proud" of him.

If the killer is Truman's father, it makes more sense why he chose him as his successor, and why he tries to train him. He is studying Truman since childhood because he already knew him, not because he found him in the tapes.

All in all, I liked "The prodigy". It could have been better, but also a lot worse with that budget. A good effort from director and actors.
7/10