The problem with capital punishment is that it is the ultimate final sentence. Should evidence come to light later that throws doubt on the conviction (as has happened many many times) you can let someone out of prison. You can't let someone out of a grave.
But what about the criminals who are absolutely positively guilty? The criminals that have confessed? Etc. Etc.
There is always some level of doubt in a conviction or a plausible cause of the actions that does not involve the criminal nature of the person themselves. In the UK over the last twenty years, I can think of people convicted of murder and subsequently released as a result of:
- Police fabricating evidence (Birmingham Six and Guildford Four)
- Forensic techniques later proven to be unreliable
- Brain tumour, which caused random acts of extreme violence and hallucinations
- Eye-witnesses later proven to have ulterior motives and shown to have lied under oath
I don't think that any criminal conviction can be 100% beyond doubt in perpetuity. And therefore it isn't just to have a punishment that puts the person 100% beyond release in perpetuity.
In the past 35 years, 129 people were sentenced to death and subsequently released from death row in the USA. Between 1973 and 1995, 5% of all capital convictions ended in the person subsequently having their conviction quashed. Others whose sentence was overturned were retried and found guilt of 'lesser' offences. The Innocence Project has proved, using post-conviction DNA-testing, that
218 death row prisoners were innocent and secured their release. They've secured pardons or retrials (ending in acquittal) in other cases where the sentence was something other than death.
Take this
bloke's case as an example. Curtis McCarty was sentenced to death in 1982 for the murder of 18 year-old Pamela Willis. During his first trial, a government forensics expert said that hairs found at the scene matched those of McCarty and that semen collected from the victim matched McCarty's blood type. The forensics expert changed her notes during the case; something only discovered 18 years later when said forensics expert was arrested for fraud. The District Attorney also withheld evidence from the defence and jury. The conviction was overturned two years later and a retrial ordered. During the second trial, the judge misdirected the jury and a re-trial was once again ordered. The third and final trial confirmed the death sentence.
In 2000, with the forensics expert, Joyce Gilchrist, under investigation for fraud relating to fabrication of results, the defence asked her to produce the hair samples which she had testified matched McCarty's. The evidence had conveniently been lost. In 2002, McCarty's lawyers were able to secure DNA testing on the sperm sample found on the victim's body. In 2005, McCarty's lawyers were able to secure a new trial based upon Gilchrist's proven unreliability and bad-faith destruction of evidence. Further forensic evidence showed that skin scrapings taken from under the victim's fingernails did not match McCarty's and a bloody footprint left at the scene could not have been made by him either. Before the third trial started, the judge dismissed the charges and released McCarty. He'd spent 22 years in jail and 18 years on death row. And he was innocent.
There's also arguments about the effectiveness of the death penalty as a deterrent. Or more to the point, it's complete lack of effectiveness. The ACLU have quite a
detailed section on it, but of course it should be read in the context that the ACLU is against the death penalty and will only publish evidence that supports their stance.
Bookmarks