Who Killed Bambi's Mom?

Awwww :-( but I couldn't resist
So check out the Rabbits with Guns I was considering

Bit by bit the clues surface and it seems it wasn't a random hunter who killed Bambi's mom. She was murdered. And Bambi's out to hunt down who was behind it.

What was she up to and who was she a threat to? Was Aunt Ena jealous? Or was the purpose to orphan Bambi? Or was it a warning to Bambi's father?

The Disney movie and Felix Salten's book have slightly different characters and sequences of events. Feel free to draw from either.