A quick bullet?  Too good for beasts like that.  I'd rather see them be locked in a cage, beaten and starved and force fed food laced with literal shit.  Their fat reserves would certainly keep them alive longer than the poor girl that they so horrendously abused.  I fully believe in the prospect of an eye for an eye, and there are certainly fates worse than death that you can inflict upon shit pieces of garbage like this that would make them wish they were dead. The only positive to this story is that the girl doesn't have to suffer anymore.