Why should we stop capital punishment?

Capital punishment is forbidden in Ukraine. It was abolished in the beginning of Ukrainian Independence. Is it right? This question contains a lot of pitfalls which must be avoided.

In some countries murder, embezzlement, money loundering, drug-trafficking, harassment,smuggling, perjury etc. are punished with death penalty, for example in China or different muslime countries. Do these organized and not organized crimes deserve to get the highest measure of punishment? Do tyey deserve such a severe retribution? But it is the infringement of human's statutory right for life! As far as I am cocerned, only serial murderers must be executed.  But what if prisons are replete, there is no place to lock criminals up because there are too many inmates in jails, what then? Do you know that confinement inmates in cells is very expensive and cost our tacks, especially when they are convicted for life sentence, it's cheaper to kill them. Not everything is so clear in this question, we must take into account every detail and punish only the most severe offenders.