I think a big part of the issue is that the young woman in question died in the hospital, and thus wasn't allowed to experience some amount of closure in regard to seeking justice against the men who assaulted her.
I've had to research a lot of heinous acts in my lifetime for my job, and that's one that -- to me -- definitely earns the perpetrators a death sentence. Capital punishment is a very gray area, in that no matter which side you take you're considered to be a monster by some. I believe that most advanced societies put delays in place because they don't want to develop a reputation for executing people who later turn out to be innocent or turn out to have been experiencing circumstances beyond a normal person's control.
The difference between "delayed" and "denied" is another gray area. It's irresponsible for someone to imply that in all cases a delayed execution (in this case, delayed beyond the survivability of the victim) is denying justice for the victim. Perspective plays a big part in how any of that is interpreted, and -- to my knowledge -- there's no word on if the victim had wanted to live long enough to see the men who had assaulted her be executed. For the families and friends, I'm sure that knowing that the men were caught and judged by the state is enough to say that they weren't denied justice.
This brings to mind the story of a priest
in Georgia named Rene Robert, who in 1985 had signed a "declaration of life" that explained that if he was ever murdered in such a manner that it would warrant the death penalty, the killer's life would be spared. On April 10th of last year, he was abducted and murdered by an ex-con named Steven Murray, of whom Rene Robert had counseled and aided. Everyone who was close to Rene Robert want his wishes to be honored.
My take; the death penalty is necessary, but only to set a precedent. People killing other people will never go away, I prefer to live in a world where there's a deterrent like the death penalty for people who committed acts of moral apathy that make them into absolute abominations unto society. I also prefer to live in a world where DNA testing is something that's used well before someone is being recommended for the death penalty. There have to be delays because nations have to weigh every implication of the given sentence, even if it's unanimously approved by the rest of the world.