19 March 2015 :

“If a person is given a death sentence, what is his or her chance of actually being executed? Based on a review of every death sentence in the United States since 1973, the beginning of the modern era of the death penalty, we have found that the most likely outcome isn't being executed or even remaining on death row as an appeal makes its way through the courts.
In fact, the most common circumstance is that the death sentence will be overturned.
From 1973 to 2013, 8,466 sentences of death were handed down by U.S. courts, and 1,359 individuals were executed - only 16 %. Those sentenced to death are almost 3 times as likely to see their death sentence overturned on appeal and to be resentenced to a lesser penalty than they are to be executed. Here is a summary of the outcomes: 8,466 death sentences were imposed across the United States from 1973 through 2013. 3,194 were overturned on appeal, composed as follows. For 523, the underlying statute was declared unconstitutional. For 890, the conviction was overturned. For 1,781, the death penalty was overturned, but guilt was sustained. 2,979 remain on death row as of Dec. 31, 2013. 1,359 were executed. 509 died on death row from suicide or natural causes. 392 had their sentence commuted by the governor to life in prison. 33 had some other outcome or a miscellaneous reason for being removed from death row. Execution is in fact the 3rd most likely outcome following a death sentence. Much more likely is the inmate to have their sentence reversed, or to remain for decades on death row. By far the most likely outcome of a U.S. death sentence is that it will eventually be reversed and the inmate will remain in prison with a different form of death sentence: life without the possibility of parole. Why would reversal of the sentence be the single most common outcome of a death sentence? Capital trials have many unusual characteristics, but a key one is that there is an automatic (or "direct") appeal through the state appellate courts and, if the death sentence is not overturned by the state appellate or supreme court, a review by a federal judge.
Throwing out a duly enrolled conviction is not something that state or federal appellate courts do because of a misplaced paperclip on a brief.
State appellate courts and federal judges are not knee-jerk opponents of capital punishment; they participate in a system that imposes it regularly. But both Republican and Democratic appointees have voted to overturn these convictions because they so often involve such issues as evidence withheld from the defense, improper instructions to the jury, or other serious flaws in the original trials.
States differ greatly in the degree to which they carry out their legal promise of death, but most operate systems consistent with the trends above: They sentence far more inmates to death than they actually execute.
The average state has a 13 % likelihood of carrying out a death sentence. Some states - such as Texas, South Dakota, Missouri, and Oklahoma - significantly higher rates, though none of these states reaches a level of 50 %. In fact, only one state, Virginia, has executed more than half of the inmates it has condemned. Several states have not executed a single person, though New Jersey sentenced as many as 52.
Pennsylvania and California have very large death penalty systems, but extremely low rates of executing those who have been condemned. Texas, Florida, and California have all condemned more than 1,000 individuals to death in the modern period. However, the numbers of executions in these states are 508, 81, and 13, respectively. Virginia has sentenced 152 individuals to die, and 110 have been put to death. Regardless of one's view of the death penalty in principle, these numbers raise questions about how the death penalty is applied in practice.
The wide differences across states in the odds of carrying out a death sentence are potentially troubling from an equal protection standpoint. Also potentially troubling is the simple fact that most death sentences do not result in executions. In fact, a federal judge recently ruled that California's death penalty is unconstitutional because it is in fact a penalty of "life in prison with the remote possibility of death."
Ultimately, the American system of capital punishment arguably creates unnecessary suffering for both those defendants sentenced to death and the surviving family members of the victims of the crimes for which the defendants were convicted. A system that ensures prolonged court time, automatic appeals for the convicted inmate - most of whom are eventually successful - and only a small chance of actual execution is a system built on false promises for everyone, and indeed one that seems to verge on torture.”