Last month, yet another Australian juror caused a mistrial because he looked up the definition of ''beyond reasonable doubt'' on the internet. This juror now faces being charged with a criminal offence. It is commonsense and instinctive to some people to refer to the internet to find an answer to any question. If NSW jurors do this, they can be jailed for up to two years.

An increasing number of trials are aborted because of jurors playing detective. In the US, 21 trials were overturned in 2010 because of such (mis)behaviour. In a New Zealand survey, there were jurors who admitted to doing their own research in more than 10 per cent of the trials. The researchers observed the jurors ''did not seem to appreciate the importance, or did not understand the logic, of restricting themselves to the information presented by the parties and the judge''. The innocent behaviour of the West Australian juror who asked the jury keeper to copy internet maps for his fellow jurors, highlights how logical such behaviour is to jurors. This juror did not regard obtaining maps from the internet as forbidden research. The maps were relevant because there was conflicting evidence about where the victim had been assaulted. The maps showed the alternate crime scene which the map provided by the prosecution did not.

"In a knee-jerk response to the rise of the detective juror, the NSW government made it a criminal offence for jurors to do research. No research into this issue was conducted before this law was made." Credit:Steve Baccon

In a knee-jerk response to the rise of the detective juror, the NSW government made it a criminal offence for jurors to do research. No research into the issue was conducted before this law was made. There are three reasons this law is wrong. First, the law has not stopped detective jurors. In the largest Victorian terrorism trial, the jurors were warned five times not to do research. Wikipedia-type internet printouts were found in the jury room. Later in that trial, a dictionary was found in the jury room. Even though the jury had blatantly defied the law, none of those jurors have been charged. And nor should they be. The average juror of the 21st century is well educated and capable of using a dictionary appropriately.

Secondly, this law is likely to undermine the most powerful weapon we have to rein in jury sleuthing. Errors made by one juror are frequently corrected by others. If a detective juror attempts to share illicit information with fellow jurors, another juror is likely to stop it and may even report it to the judge. However, fellow jurors are discouraged from reporting detective jurors if they think that the juror will go to jail. In a NSW trial, two independent witnesses reported that a juror had contacted a journalist and some jurors were planning to visit the crime scene. When questioned under oath, not one of the 12 jurors ''dobbed'' on their own.