Yes, you have to attempt an arrest first. Poaching is not a capital crime.
Importantly, this isn't poaching. This was lawful collection of elephants. Morality aside, this does provide funding for cash- strapped nations and some of that funding goes to protection of stressed animal populations.
Yeah let's not do that.
I personally dislike zoos and don't visit them. At the same time, I'm not comfortable telling you how you should feel.