Your idea of 'execution' is nothing more than instilling even more violence (ie that of retribution and vengence) into our society, and what's worse is that it would be sanctioned by our very own government. Utterly abhorrent, uncivilised, simplistic and a step back to the dark ages.
We as a society are much better than that.
In this day and age we should be able to deal with any offender, regardless of their crime, with level headedness, and without resort to barbarity. There are means of punishment and rehab that have been developed over hundreds of years to get to where we are today and the result is a humane, free and just society which, believe it or not, is the envy of many other countries. Do you really think it is that bad in the UK? I'll bet you haven't travelled far, and a week in Ibiza doesn't count.
You're a sadist who be "first in line to sign up for the job" of executioner.
You also talk about our 'rapidly decaying planet'. What planet are you on?