why the death penalty should be abolished reasons?

why the death penalty should be abolished reasons?
It is irreversible and mistakes happen. Execution is the ultimate, irrevocable punishment: the risk of executing an innocent person can never be eliminated. ...
It does not deter crime. ...
It is often used within skewed justice systems. ...
It is discriminatory. ...
It is used as a political tool.
Full answer in: www.amnesty.org