But they were still a mob, and what they wanted to effect was a grave injustice. By rallying to force a change in the verdict, to demand that politicians ride in over the decisions of unelected judges and "change the law" so that "something like this" can "never happen again", the well-behaved mob in bright yellow frocks and shirts demanded a change that would ensure grave injustice was done to the victims of domestic violence as yet unscarred, even unborn. Thousands attended the rally for Allison Baden-Clay in King George Square on Friday. Credit:Robert Shakespeare There are two issues, one of principle and one of practicality. The first principle, the separation of powers, exists to ensure that power seekers whose interests are always short term and self-serving cannot debauch the justice system simply to entrench themselves in office. Yes, judges are unelected. Yes, they are even unrepresentative, and they really do make some very unpopular decisions sometimes.

But that's how the system is designed. It's not a fault, it's a feature. The justice system has to be that way, unless you want the outcome of criminal trials determined by, say, an internet poll or a phone-in ballot of the sort used to pick the winner of a reality TV show. By rallying to force a change in the verdict, to demand that politicians ride in over the decisions of unelected judges, the well-behaved mob in bright yellow frocks and shirts demanded a change that would ensure grave injustice was done. Credit:Robert Shakespeare Hell, if you really want to go down that path we don't even need all the tech. We could gather once a week in King George Square and cartloads of accused ne-er-do-wells could be paraded before the mob to plead their case. Why bother with courts after all, when a couple of thousand angry punters are on hand with pitchforks and burning branches? An exaggeration? Sure. And a grotesque one, but it is the logical end point of doing justice by base populism. The second issue, a practical question, arises as soon as we "change the law" so that "something like this" can "never happen again".

We long ago settled on the difference between manslaughter and murder because they are very different crimes, even if the outcome, a killing, is the same. If Allison Baden-Clay had picked up a kitchen knife and run her husband through as he advanced on her with violence in his eyes, would she have to be condemned as a murderer? What if in fighting him off she'd picked up a blunt object, a rolling pin or fry pan let's say, and clocked him upside the head? Not a blow to kill a man, perhaps, unless he struck his temple on the sharp corner of a marble bench as she felled him when defending herself. Too bad, says the mob, she's a murderer. There are infinite variations on this scene and they have played themselves out time and again over hundreds of years of legal history. Few things are as simple as the feelings of revulsion and outrage felt by the supporters of Allison Baden-Clay. But those feelings are not a good basis upon which to build a justice system.