Meanwhile, the minister is bringing together a select group of New Zealand and international specialists to map out new ways to deal with crime over the next 10 years.
Ms Collins said she would be open to any new idea that worked, and quite radical ideas.
She said did not want lobbyists at the symposium, to be held at the end of April, and about a quarter would be specialists from overseas.
"We are going to do some blue skies thinking," she told the Herald.
She wanted to hear from victims of crime and even former offenders who had undergone successful rehabilitation, but she wanted a research-based symposium and expected a number of papers to be presented.
New Zealand and overseas judges would be invited, as would people involved in prisoner rehabilitation, lawyers, and opposition MPs.
The Better Public Service targets in the justice sector were on course to be reached well before 2017 with the crime rate to a 33-year-low, the prison population dropping and 19 per cent fewer prosecutions last year.
"We don't want to rest on our laurels and we don't want to get bogged down in just focussing on getting to the targets we know we are going to achieve.
"We want to take ourselves up to another level over the next 10 years so it's a big thinking project."
One of the initial targets was to reduce youth crime by five per cent by 2017. That has been exceeded with a drop of 19 per cent between 2011 and 2013 and the target has been reset at a 25 per cent reduction.
The sector's other targets remain the same - a 15 per cent reduction in overall crime, a 20 per cent reduction in violent crime and a 25 per cent reduction in re-offending by 2017.