Overcoming opposition from China, U.S., and Iran, the UN General Assembly passed a resolution today "calling for a moratorium on the death penalty, with the ultimate aim of abolishing capital punishment." Amnesty International heralded this moratorium as an important way to "encourage retentionist countries to review their use of the death penalty."
104 UN member states voted for the resolution. The opposing countries (such as China, Iran, Iraq, Pakistan, Sudan and the U.S.) account for ninety one percent of all capital punishment.
Whether capital punishment is a matter of human rights or criminal justice seems to be a key question. Criminal justice is considered to be a country-specific decision (in the U.S., capital punishment is primarily governed by state law), and some countries like Singapore have decided to disregard the UN and continue to implement policies they see fit. Whatever your opinion on the death penalty, it doesn't hurt to look at some relevant public advocacy and educational material.