A new Pew Report shows support for the death penalty for convicted murderers has dropped to 55%, the lowest level since the 1970's. Among the reasons:

...a steep drop in the incidence of violent crime, and greater attention to wrongful convictions, which has led to more than 1,300 convicts being exonerated through DNA evidence, revelations of faulty forensic work, or other means. (Recent reports of prolonged executions and the difficulties many states have had in procuring drugs for lethal injections also may be factors in shifting public opinion.)

Since 1973, the U.S. has executed 1,373 people. According to the National Registry of Exonerations, 1,339 people have been exonerated since 1989, 106 of whom were sentenced to death. Only 1/3 of the exonerations involved DNA evidence.

All but two of the executions were at the state level. The highest number of executions: Texas, with 512. After that: Virginia and Oklahoma (110 each), and then Florida, Missouri and Alabama.