Comment: After Amanda Knox, the capital punishment debate is over

The Knox trial shows why we can never be confident enough to support capital punishment.

By Ian Dunt

When Amanda Knox left her jail cell, she forced people to do a lot of soul searching. From the cynicism of the tabloid press to the inadequacies of the Italian justice system, there was a lot to talk about. But it was capital punishment proponents who should really be given pause for thought. Today is World Day Against the Death Penalty and the facts have conspired to make the argument water-tight.

Even in the UK, where the reintroduction of the death penalty is unthinkable, we need to grab the oppourtunity it offers us. This summer, the right-wing blogger Guido Fawkes tried to start up an e-petition to reintroduce capital punishment. That attempt spectacularly backfired, killing the myth there is a massive groundswell of support for the practise among voters. Government e-petitions require 100,000 signatures to be debated in the Commons. All of us, including opponents, assumed it would be a shoo-in. Actually, Fawkes' effort barely made it past the 20,000 mark. The debate around the e-petition allowed us to comprehensively demonstrate that capital punishment is not a deterrent. Its failure showed there is no mass public support for it. Now, as events highlight the weakness of sophisticated western judicial systems, we can demonstrate why it is impossible to ethically justify executions.

As Knox prepared to leave Italy, something interesting was happening back in her home country. Tuesday October 4th saw three men walk free from jail. Michael Morton of Texas was exonerated of killing his wife in 1986 following new DNA tests. Jacques Rivera of Chicago was released from jail after a 1990 conviction for gang-related murder was found to be based on false evidence. Finally, Obie Anthony of Los Angeles had his 1994 conviction for murder overturned after it emerged that the star witness in his case had lied after cutting a deal with the police.

All these cases had the Innocence Project to thank, a remarkable organisation set up in 1992 to exonerate people through the use of new DNA technology. So far, it has seen 250 exonerated – 17 of them on death row. It's assessment of the factors which tend to result in wrongful convictions is reflected by the Knox trial.

Of course, there are good reasons to suspect Knox. She confessed to being in the house on the night Meredith Kercher was killed, for a start. Even if the confession was made under duress, as she claims, she repeated it in a five-page memorandum the next day. Her boyfriend Sollecito could not back up her alibi and their mobile phones and computers did not substantiate their accounts of the evening.

But the reasons Knox was acquitted tell us a great deal about the fundamental flaws in all justice systems, flaws which make the moral argument for capital punishment impossible. Prosecutors claimed Knox's DNA was on the handle of the presumed murder weapon (a kitchen knife). Kercher's DNA was found on the blade, they said. Sollecito’s DNA was found on the clasp of her bra. A review from two independent experts from La Sapienza University in Rome found the DNA samples to be too low to be reliable and so tiny they could not be retested. The bra clasp was found six weeks after the initial crime scene investigation, when it could have been subject to several contaminations. The knife itself did not match two of the three wounds on the victim's body or the bloody smear on her bedclothes.

It’s tempting to write that off as Italian police incompetence, but it would be inaccurate. In fact, failures in DNA technology and practise are responsible for many wrongful convictions – and the public sense of its reliability makes the problem even worse. While DNA testing is a sound method, other techniques have not been subject to proper scientific evaluation. These include hair microscopy, bite mark comparisons, firearm tool mark analysis and shoe print comparisons. Those techniques that have been properly tested, including blood typing, are often improperly conducted or inaccurately conveyed.

Knox's case was also assisted by the eyewitnesses, who were desperately unreliable. A homeless drug addict, Antonio Curatolo, testified that he saw Knox and Sollecito arguing near the scene of the crime that night, but on appeal his evidence was confused and contradictory. Rudy Guede, the Ivory Coast-born man also convicted of the murder originally said Knox was not at the house, but he changes his story months later, saying he spotted Knox's silhouette outside the building.

This kind of inaccuracy is par for the course, with the Innocence Project saying eyewitness misidentification is "the single greatest cause of wrongful convictions" in the US, playing a role in over 75% of convictions overturned through DNA testing. Eyewitness testimony is very convincing to judges and juries, but it’s not as clear cut as you think. The human mind is not a video recorder. It is a shambles, frankly, mixing and matching memories with assumptions and emotions. Identifying someone of a different race is famously dodgy and witnesses are very likely to offer inaccurate assessments when the situation was one of distress or heightened emotions, which it usually is. Moreover, the moment concerned rarely happens clearly in the light of day, but often out the corner of the eye in a darkened environment.

Even when you discount the human errors, police tend to make serious mistakes when collecting witness statements, including conducting line ups while knowing the perpetrator, selecting fillers under inappropriate circumstances and being consciously or unconsciously suggestive when instructing witnesses.

The inclusion of Guede's testimony highlights how unreliable witnesses can be used in trials. But at least jurors would have known of Guede's conflict of interest. Many jurors aren't so lucky. They are not informed that informants are used. They are not informed when witnesses are paid to testify. They are not informed when witnesses are offered their freedom from prison. They are not informed when witnesses are testifying as the only way to avoid jail.

Knox's confession is also standard. The defence argued that Knox was emotionally traumatised when she gave the confession. At the time she had her hands cuffed above her head by a police officer and was being threatened with decades in jail. She was questioned without a lawyer and could only use basic Italian.

In about 25% of US DNA exoneration cases, innocent defendants made incriminating statements, delivered outright confessions or pled guilty. Sometimes it is simply the emotional duress, sometimes it's because they are under the influence of drugs or alcohol, sometimes they are mentally handicapped or being threatened by a harsh sentence. Many people later say they were under the impression they could go home, that the whole situation would finally stop, if they just do what they were asked.

The Knox case was particularly inept but the errors are not unique to Italian justice. They are present across the world, because they rest on new technologies and human fallibility. The idea that one man should be put to death by the state for a crime he did not commit is insufferable. But it has happened, it does happen and if capital punishment proponents have their way it will happen again. If the circus around Knox demonstrates anything, it's that. In the face of uncertainty, there is no moral basis for capital punishment.

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