Death penalty still the norm?

I recently read this story

The Iranian woman was executed out of self defense. I was shocked however, is death penalty still the norm in our society. In many countries for example, in Philippines where the jails are over crowded I think death penalty is applicable to people who have really murdered someone out of selfish reasons.

In certain countries like the Philippines it is hard to implement this as the Catholic Church is very dominant in the country. However in many countries like Iran it is implemented and at times used to take advantage to execute innocent lives.

Is it morally wrong to say to give someone a death penalty in our society regardless whether he was really guilty or not? What are you thoughts. Personally for me it is a huge dilemma as different countries may find it useful.

What I have noticed is that countries that have death sentence have commonly stern Governments. People in those certain countries generally follow their Governments and are content with them. However in countries with no death sentences the Governments are generally not as strict and strong.

Do you think punishments like death penalty should be present in our society to maintain peace and order or do you feel it is not needed? What other ways do you think can be done to have peace and order in the country?