BartSimpson BartSimpson:
The thing to do to prove either point is to draw up two lists:
1. A list of murderers who've killed again in prison or after their release from prison.
2. A list of murderers who've killed again after being put to death.
The list with a 'zero' at the end will tell you which process makes innocent people safer.
As to who is put to death the one thing I truly insist on is that no one should EVER be put to death on circumstantial evidence. I don't care how 'logical' it is that a certain person could be the only person to do the crime if there's no actual evidence to prove it then put the person in jail for life. In all of the cases where people have been wrongly executed it's because they were executed on circumstantial evidence and when actual physical evidence was later analyzed they were exonerated.

You're missing a list there - all the people put to death who were innocent. Included a best estimate of those who were likely innocent but never investigated.
Ps, just read Hurley's post - he said it better than me.
If you're not going to kill on circumstantial evidence, you won't be killing many people. Physical evidence can't prove guilt beyond a reasonable doubt, only exclude it. Then read what forensic associations say about reliability of physical evidence. CSI is just a TV show. Eye witness testimony has been shown to be very problematic. So basically you've got video evidence - pretty rare.
The (supposed) rapist on death row who was exonerated by DNA was not convicted on circumstantial evidence, but on the evidence of his victim.
Since you'll be killing so few people under your scheme, much cheaper to just abolish the death penalty and have life w/o possibility of parole.