I think it's pretty extremely likely they were taunting the tiger (and - tiger's don't speak English - when I speak of 'taunting' the tiger, I don't mean making stupid knock-knock jokes, or making noises - that's hitting it with a BB gun (my first guess) or other missiles) - this tiger has been there for quite some time, and the first time it decides to jump the wall and attack someone, it's some kids with a bad history who won't talk to police? That seems far, far, far too great of a coincidence, that on that day, just at random, the tiger jumps out, and just at random happens to attack, out of all the people there, these 3 guys.
As to, justified - I can understand saying that. You go mess with an animal that can kill you, and you've chosen your fate. Now, doing so at a zoo is a cowards choice, attacking an animal because they're helpless to retaliate. It's a disgusting act, it's something that often is the first step to bigger crimes. Assuming the slingshot is true - and I think so - these guys went to the zoo because there were animals in cages that they could torment, they could enjoy hurting, without any risk of the animal being able to strike back. That's pretty sick.
I don't know about the third guy - I suspect he was a patsy, a fool going along with some buddies - but the two brothers, their actions before, during, and after show a character that is rotten to the core. Anyone with any decency would have at least told the father where his son was, or called to say sorry, to answer his questions, or done some small thing, anything, to try to lighten his grief.
with BRATTY children and no longer am I asked to help her!
