Chances of conviction higher in Canterbury
Cantabrians accused of crimes are more likely to be convicted in court than those elsewhere in the country, statistics show.
Statistics NZ data shows 84 per cent of adult criminal prosecutions brought in Canterbury last year resulted in convictions. Nationally that figure was 74 per cent.
The national conviction rate has remained fairly constant since January 1, 1980, when 79.2 per cent of prosecutions resulted in convictions. It has declined ever since, reaching a low of 67.4 per cent in 1984.
The median, or average, rate since 1980 was 72 per cent.
The conviction rate in Canterbury has averaged 77.6 per cent since 1980.
The data, called "the number of charges finalised in criminal courts during a calendar year", is collected by the Ministry of Justice..
Taking population growth into account, there were about 13,000 recorded offences per 100,000 people in 1996.
That fell to about 8000 recorded offences per 100,000 in 2013.
"By and large, offences have dropped by a factor of a third," Statistics NZ analyst Alistair Ramsden said.
Recorded offences do not necessarily result in prosecutions.
One outcome, called "unfit to stand trial or insane", increased from three incidents in 1980 to 305 in 2013. The rate more than doubled from 2010 (194) to 2011 (399).
"At first glance we're not aware of any particular reason that resulted in that increase," Ministry of Justice spokesman manager Antony Paltridge said.
The numbers had "dropped back since then and historically the figures have fluctuated up and down", he said.
University of Auckland law professor Warren Brookbanks, who has written extensively on unfit to plead and insanity law in New Zealand, was unable to pinpoint why the rate doubled in 2011. "Part of the general explanation is a change in legislation in 2003, which provided greater opportunities for lawyers to test issues of unfitness to stand trial," he said.
"Lawyers have been quick to exploit opportunities for litigating these issues."