But what does this really mean? A well-known saying attributed to Mark Twain states: “There are lies, damned lies, and then there are statistics.” This points to the potential for statistical data to be misinterpreted to support a weak argument.
So what’s the weak argument? The claim that 55% of prisoners have committed sexual or violent offences is weak because it only applies to those in prison on a given day – in this case December 31, 2022. It’s a one-day snapshot. This statistic was used by Mark Mitchell to criticise and ridicule Green MP Tamatha Paul, who recently claimed that “the vast majority of people who are in prisons are there for non-violent offences”.
But this briefing was supposed to provide long-term insights. So let’s look at the criminal profiles of those sentenced to prison over a 12-month period.
Currently, the prison muster is just over 10,000. However, in any given year, around 20,000 New Zealanders spend time in prison and about 15,000 are released every year. This occurs because the majority of those sentenced to prison are given short sentences.
The reason these offenders receive short sentences is because their offending – such as shoplifting, theft, driving while disqualified, breaching court conditions etc – is not serious enough to warrant a long-term sentence. None of this involves interpersonal violence. Offenders given a sentence of two years or less are automatically released halfway through the sentence. That’s why there’s a high turnover.
The long-term briefing relies on statistics from the Corrections Department, which reports that about half of those currently in prison are serving long sentences for sexual and violent crimes – that’s about 5,000 inmates, 50% of the daily total, but only 25% of the 20,000 who spend time in prison each year.
So Tamatha Paul was on the right track. It may not be the “vast majority” as she claimed, but around 75% of those who end up in prison every year are there for non-violent crimes. That’s a substantial majority.
But these are broad-sweep statistics. I did a deeper dive for more specific data by making an Official Information Act (OIA) request to the Ministry of Justice, asking for a breakdown of the criminal profiles of every offender sentenced to prison in 2024. Those convicted of serious violence (murder, manslaughter and other acts intended to cause injury) made up 1.7% of the total; those convicted of aggravated sexual assault made up 6.3%. Adding these figures together means those sentenced to prison in 2024 for serious violence or aggravated sexual assault make up only 8% of those sentenced to prison that year.
However, the Ministry of Justice data distinguishes between “acts intended to cause injury” (serious), “common assault” and “assault not further defined” (less serious). It says 22% of prisoners were sentenced for the latter two offences. Adding the serious and less serious figures together, about 30% of those sentenced to prison in 2024 were convicted of violent or sexual offending. Turning that around: 70% of those sentenced to prison are there for non-violent offending. That’s still a substantial majority.
That’s still not the end of the story. What constitutes “less serious” violence? Here’s one example. Remember Daniel Fitzgerald? In 2018, he was sentenced to prison for seven years for indecent assault when he kissed a random woman in public. After more than four years inside, the case went to the Supreme Court which said his imprisonment went “well beyond excessive punishment and would shock the conscience of properly informed New Zealanders”. This travesty of justice occurred under the Three Strikes law – which was intended to address serious violence.
How many of the 22% sentenced to prison for less serious violence might not be there if it weren’t for Three Strikes?
That would take another deep dive. But clearly, the pool of violent offenders is nowhere near as deep as Mark Mitchell and the Corrections Department would have us believe.