CHINA’s execution of a South African drug mule yesterday reminded me why I am opposed to the death penalty and, oddly, why I think Democratic Alliance leader Helen Zille is misguided in pushing for the prosecution of those who knowingly pass on HIV.

Not that I have any moral objection to the state stringing up people who are guilty of serious crimes. A premeditated killer’s right to life must surely be limited by society’s right not to be deprived of theirs. The Constitutional Court didn’t see it that way, of course. Nor do I have an issue with Zille’s point that the only way we are going to get on top of the HIV/AIDS pandemic is by insisting that people take responsibility for their actions. The lack of a culture of accountability is at the root of almost all of SA’s social and political problems, so I’m all for ensuring wherever possible that people face the consequences when they act irresponsibly.

In the case of both judicial killing and prosecuting those who knowingly pass on HIV, the reason I am opposed is that these measures don’t work and the risk of unintended negative consequences is too high.

Killing people who commit heinous crimes is a pretty efficient way of ensuring the hapless individuals concerned never repeat the antisocial behaviour that landed them on death row, but it does little to dissuade others from doing so. That much is evident from the fact that Janice Linden chose to smuggle 3kg of crystal meth (tik to Capetonians) into China three years ago.

This assumes that Linden, who was executed by lethal injection yesterday, was actually guilty and not an unwitting carrier of the drugs, as she claimed to the last. But if she was innocent, that is even more reason to oppose the death penalty — ending someone’s life is one mistake you cannot correct.

There’s an even more compelling reason advocates of the death penalty are missing the point though, especially in SA. It is that to execute someone you need to catch him first. The biggest problem with the South African justice system is not at the punishment end of the process but at the policing end. The most effective crime deterrent is the certainty of being caught, and we just don’t catch a high enough proportion of our criminals for the threat of severe punishment — even death— to be a deterrent. Ironically, if we caught and jailed more criminals, there would be less crime and public support for the death penalty would almost certainly decline.

Zille’s desire to encourage HIV testing and discourage promiscuity — especially having multiple concurrent sexual partners — cannot be faulted. And she is probably right that the reason the latter problem hasn’t been tackled with any enthusiasm in SA is because criticising polygamy is politically incorrect now that we have as our president such an enthusiastic practitioner of this archaic tradition.

However, the way to increase the number of South Africans who know their HIV status is not by prosecuting those who pass on the virus. Again, morality doesn’t come into it — of course, those who have unprotected sex when they know they are HIV- positive are morally reprehensible, and probably guilty of a crime — but what is achieved by prosecuting them for attempted murder (or rape, on the basis that there can be no consent without disclosure)? For a start, it is exceedingly difficult to gather enough evidence to get a conviction, even if the unwitting partner contracts HIV. Reasonable doubt is a tough hurdle to overcome at the best of times; it is nigh on impossible to establish when the only witness is the complainant and the closest you can get to forensic evidence is a matching strain of HIV.

But the most compelling argument against taking the criminalisation route to encourage accountability is that it is likely to have the opposite effect. After all, if people don’t know their status, they can’t be accused of knowingly passing on the virus, so wielding the big stick will just undermine efforts to promote the HIV-testing campaign. I share Zille’s frustration with the fact that a lack of accountability is condemning thousands of people to infection. But the solution has to be motivated by what works, not by what is morally or legally correct.

• Marrs is Cape Editor.