Traditional jury trials could be undermined by jurors receiving information about defendants by way of the internet, New Zealand District Court Judge David Harvey said.
Speaking at the 14th International Criminal Law Congress in Queenstown this week, Judge Harvey said that in the digital age jurors were sourcing information through the internet "rather than the archaic process of a trial".
Judge Harvey said the internet and social media carried with them a huge amount of power, and the criminal law process must adapt to those problems and challenges, such as jurors accessing information about accused and witnesses outside the trial.
He said it could be "difficult to wipe the slate clean", but potentially prejudicial material did not have to influence the jurors.
"More attention is paid to admissible evidence and information obtained in court than otherwise."
He argued for the greater use of information technology, such as electronic whiteboards and Google maps, in court, as jurors used information technology to receive information independently.
Because of the inevitability of jurors having easier access to digital information, he recommended a "proper educative process for jurors", beginning at a young age so they understood what could prejudice a trial or cause an expensive mistrial.
Judge Harvey said information sourced outside the trial was likely to pose the greatest risk for jurors: "Especially if it is shared with other jurors, but much will depend on the nature of the information".
Though he recommended jurors abstained from Facebook during a trial, he said, "You can't take people offline, and we have to adapt to that."
Before December 2008, the law required the jury be sequestered during the process of deliberation. Now it is at the judge's discretion and jurors are often free to return home during deliberation.
Speaking after Judge David Harvey, Dr John Burrows told the room of national and international criminal lawyers not to underestimate the new media.
Many news stories were broken on social media sites, and the law was still a "step behind".
"The new media does create negative impacts on the law," he said.
The internet had allowed the dominance of "citizen journalism", often by anonymous bloggers, and most of the material was incorrect.
"It is often expressed in extreme and inflammatory language ... most media these days is not written by trained journalists," he said.
"A lot of these new media statements break the law."
Before the internet, when people learned of news events by reading the newspaper, listening to the radio or watching television, information about a crime was likely to be forgotten six months down the track when a trial was held.
There would be no prejudice "because of what they called the fade factor", Dr Burrows said.
However, on the internet, an item could be regularly shared.
It could also often be shared untraceably.
Social media "will continue to thrive and develop [and] will be available much more rapidly and much more pervasively".
Dr Burrows said New Zealand had a "touching faith" in juries and if directed properly they would be able to put prejudicial material "out of their minds".
