Life is full of circumstances. That's why you're given ample amount of time to appeal before you get executed and that's why the judge has discretion to use any options available - life imprisonment, execution, probation, house arrest, etc. Be thankful that we're not the country with one punishment for all crimes like Saudi Arabia or China.
I only believe what the statistic says because numbers don't lie.
Statistic (data from NCADP - National Coalition to Abolish the Death Penalty and ACLU):
Since 1976 - 1099 executions
2005 - 60 executions
2006 - 53 executions
2007 - 42 executions
(more white people were executed than black people)
Since 1973, 129 wrongfully-convicted people were freed from death row
Since 1970s - 39 people wrongfully executed (estimated - data from ACLU)
Bureau of Justice Statistics - # of executions from 1930~2007
same as above - # of prisoners on death row
So let's do the math... 39 were wrongfully executed... 1099 executions... which means 1060 were RIGHTFULLY executed... that is 96.45% success rate of rightfully executed. According to Columbia University study (no link), we have 95% success rate (95 out of 100 people put to death) that is actually guilty of crimes. I don't know about you but I'm actually pleased with the statistic. Yes I know it sounds cold but you have to face it - world's imperfect. It's still better here than any other countries to be executed where you can be executed for cheating on your husband, stealing, smuggling, etc. Our justice system is imperfect but there's always a room to improve and correct it.