The risk of executing innocent people exists in any justice system
There have been and always will be cases of executions of innocent people. No matter how developed a justice system is, it will always remain susceptible to human failure. Unlike prison sentences, the death penalty is irreversible and irreparable.
The arbitrary application of the death penalty can never be ruled out
The death penalty is often used in a disproportional manner against the poor, minorities and members of racial, ethnic, political and religious groups.
The death penalty is incompatible with human rights and human dignity
The death penalty violates the right to life which happens to be the most basic of all human rights. It also violates the right not to be subjected to torture and other cruel, inhumane or degrading treatment or punishment. Furthermore, the death penalty undermines human dignity which is inherent to every human being.
The death penalty does not deter crime effectively
The death penalty lacks the deterrent effect which is commonly referred to by its advocates. As recently stated by the General Assembly of the United Nations, “there is no conclusive evidence of the deterrent value of the death penalty” (UNGA Resolution 65/206). It is noteworthy that in many retentionist states, the effectiveness of the death penalty in order to prevent crime is being seriously questioned by a continuously increasing number of law enforcement professionals.
Public opinion is not a major stumbling block for abolition
Public support for the death penalty does not necessarily mean that taking away the life of a human being by the state is right. There are undisputed historical precedences where gross human rights violations had had the support of a majority of the people, but which were condemned vigorously later on. It is the job of leading figures and politicians to underline the incompatibility of capital punishment with human rights and human dignity.
It needs to be pointed out that public support for the death penalty is inextricably linked to the desire of the people to be free from crime. However, there exist more effective ways to prevent crime.