The stressed prison network has had a Great Escape - a string of innovations allowing inmates and those charged with crimes better access to justice services has seen a huge fall in inmate numbers.
Our prisons now have 1000 fewer inmates than official projections and the prison population - around 10,200 - has fallen by 600 people in the past six months.
The changes haven't involved keeping out of prison any people who should have been locked up.
Instead, it has seen "embarrassingly simple" wrinkles ironed out of the system which appear to have improved people's access to justice.
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A number of smaller projects had been underway for about 18 months but Corrections minister Kelvin Davis signed off on a permanent programme in January 2018.
The programme of change has been led by Corrections deputy national commissioner Leigh Marsh.
He said he had relied on experience earned on the prison frontline and worked with courts and police staff with similar real-world experience.
Marsh said innovations included trying to understand why so many on electronic bail were "failing and clogging up the system".
When the process was studied, it was found those arrested with literacy issues were being handed complex forms to fill in that they couldn't understand.
About 70 per cent of those currently in prison have literacy level considered insufficient for modern life.
Others couldn't supply phone numbers so addresses could be checked as suitable bail addresses because the number was saved on the phone which was removed after they were arrested.
When prisoners were asked how they intended getting the phone numbers to arrange bail, they had reportedly planned writing letters to family.
Marsh said his reaction was: "This is madness. We can do better than this."
There were now advisers who were available to talk to those who were freshly remanded to better understand why they had been refused bail - and to help obtain details such as phone numbers.
Corrections was also trialling in Wellington a service aimed at assisting those applying for bail. The bail service would help those charged arrange appropriate bail addresses, and to connect with programmes needed to address offending, such as services to deal with alcohol and drug abuse.
Once in the community, there were others who worked to help those on bail understand their conditions and to connect with support which might be needed.
A smartphone app had also been developed meaning those on bail had their conditions at hand, would receive reminders of court dates and could ask for exceptions if needed rather than deal with the previous complicated telephone-based system.
Other innovations included helping those appearing for sentence find a suitable address for home detention, getting police evidence to those accused to enable faster pleas and ensuring those appearing for parole had taken necessary courses.
Marsh said the prison population had peaked in around 10,800 in March and had since trended down to around 10,200 now. It was currently around 1000 fewer inmates than Ministry of Justice predictions.
The change began to happen around the time the Government was confronted with the 3000-bed mega-prison plan for the Waikato It opted for a smaller expansion and a new mental unit for inmates, of which many have mental health and addiction issues.
He said the biggest difference had been in the remand population. The number of people sent to prison to await trial ballooned after a new 2013 law which made it harder to get bail.
Marsh said the increase in numbers on remand had led to a traffic jam across the criminal justice system.
Davis said the scheme - called the High Impact Innovation Programme - had eased pressure across the prison network. Crowding had eased in prison units, reducing stress among inmates and concern among Corrections officers.
"I just think, why wasn't this stuff done before," he said. "We haven't made changes to any laws. It's getting efficiencies in the system. We want to look at other ways we can make the system work more efficiently.
He said the current goal was to reduce the prison population before 10,000, which it was at last in 2016.
"It's a bit of a glass floor. It would be a glass floor that would be great to shatter."
Prison reformer Kim Workman - who once ran the prison network - said: "It does tend to show that a lot of what's been going on is access to justice issues."
Workman said he believed the judiciary had also caught a mood for change in the Government, with Court of Appeal president Stephen Kos speaking against longer sentences.
He said it was contrary to the previous government who had a "tough on crime thing and (were) not wanting to be seen to depart from that".