Fair to execute after 20 years punishment!!

Today's highlight is the news about the 8 weeks stay order on the execution of Rajiv Gandhi's assassin(http://www.thehindu.com/news/states/tamil-nadu/article2411422.ece?homepage=true)(Madras High Court stays execution of Rajiv case convicts for eight weeks ).While some people who feel these assasins should be executed are angry while there is another group who gave the sigh of relief atleast for 8 more weeks. After giving some thought, I got an altogether different view.
Just realized that its almost 20 years since Rajiv Gandhi's assasination. And what these assasins were doing till now? They were in Jail I guess and definitely must not be treated like king and queen. 20 years is a big time to spend behind the bars. 20 years is a "Generation". So those culprits have already missed one generation of their life doing nothing.
What they must be doing?Nothing more than thinking. Thinking about an incident that happened 20 years back. In initial days, they must be feeling triumphant for the task they carried out for their group who wanted Rajiv Gandhi dead.
With time passing this feeling must have subsidised and replaced with a guilt of killing a person. Initially they must have confronted their own feeling proving themselves that their act was right. But slowly this confrontation must also have been died down. I believe, now they are left only with this guilt. Now they might not be having any enthusiasm for life, no idea how to spend every next day coming.
Only thing remaining is feeling this guilt and waiting for the execution day. (It may be totally wrong but deep thinking on an incident for 20 years may should bring this change or else the culprit is insane).
I personally feel this is a torture.
Why should it take 20 years for an execution day to arrive(again prolonged by 8 weeks). They are getting double punishment of initially spending 20 years in Jail and then execution. If they were to be executed that should have happened immediately. Why it took 20 years?
On the contrary when I see that a terrorist responsible for deaths for ~2500 people in America was found out in another country and executed within 10 years, I feel sorry for our system. If a simple and straight case of finding culprits (in approachable range), running cases, getting decision, finalizing the decision through different sources and finally executing the culprits takes more than 20 years with still no assurance, then forget about other terrorists waiting for their execution.
There are two types: one where one gets scared of an insect and instinctively kills it. The story over. The second where one finds the insect troubling, put it in safe place (for the one) and then slowly tortures it either by pulling leg or breaking leg and doing similar stuff. By the time it dies(executed), it has already been through the hell's experience.
I think our system falls in this second type.
We call our system fair and non violent, but we forget our system is torturous for those culprits and their relatives.
We need to learn to end the story in time.