Should there be have a capital punishment?

Capital punishment is necessary for many countries. There have more countries decided to stop execution and remove death penalty. The capital punishment debate is become the trend. Many Abolitionists said “the crime rate haven’t decrease by execution, the capital punishment’s deterrence function have doesn't work.” to support their discussion. Actually, some countries’ crime rates haven’t increase after capital punishment debate. Abolitionists cannot use those data to request other countries to abolishing the death penalty. Every country has their different culture, educate environment, values. For example: in china, people have traditional concepts which like “a murderer must repay with his life”, and “people need response the effect when they do something.” In this situation, if China stops execution, this may cause many problems to make the society function properly. How can we do that? The capital punishment debate is the trend for future, but it doesn't mean abolishing is fit to some countries. The capital punishment is necessary punishment for many countries.