I will provide links to a few examples in North Carolina.
To date 17 death row inmates in North Carolina have been released from death row due to the North Carolina statute that prohibits the execution of mentally retarded or low IQ inmates. The statute has been abused severely. Recently, three North Carolina inmates were released from death row because of the Racial Justice Act. Two of them were convicted of killing Highway Patrol Trooper Ed Lowry in1997.
http://www.wral.com/news/local/story/10678344/
http://www.wral.com/news/local/story/10593130/
http://www.wral.com/judge-race-a-factor-in-picking-juries-for-death-pena...
Where are the victims rights? But, that aside, the root of these acts and statutes have been violated and abused.