Former National MP Chester Borrows has called on politicians not to bow to public sentiment to be "tough on crime" or give knee-jerk reactions to individual horrific crimes, as National had done in 2012.
Borrows, a former police officer and National MP until 2017, is the chair of Justice Minister Andrew Little's new advisory group on criminal justice which will report back early next year.
Borrows was courts minister in the National Government, but has made no secret that he has a different view from many National MPs on the "hard on crime" line.
Speaking at the launch of the working group at Parliament, Borrows said the advisory group was not "politically bound" so could explore areas politicians steered clear of in case they were not palatable to the public.
National Party leader Simon Bridges has already criticised Little's plans to reform bail and parole laws, saying it would put the public at greater risk.
Borrows said it was tempting for political parties to take the "hard on crime" line for political reasons but it did not make good law.
"It's a fish-hook for political parties that they want to be seen to be doing something.
"You've always got a Budget or an election around the corner. Thankfully this group won't have to worry about that."
He admitted that behind closed doors he had argued against National's overhaul of bail laws after a campaign to toughen bail laws following the murder of Christie Marceau in 2011.
"Yes, I did but as you can tell you don't always win the argument.
"National would argue there was a reasoned and smart debate early on, but as you get more and more into defence mode and as a Government you are dealing with incidents the tendency is to rush off and change the law on the back of one-off incidents to be seen to be doing something."
Little is also planning a summit in August as he prepares reforms which he said were aimed at reducing offences and repeat offending.
National MPs would be invited to that summit.
"But their rhetoric so far indicates the approach they are taking."
He said he was hopeful for an "adult conversation" about it.
Those pleas appeared to fall on deaf ears - Mark Mitchell, National's justice spokesman, said the planned summit was "public relations exercise" aimed at justifying a "soft on crime" approach.
He said the outcome of the process was pre-determined as shown by the decision to downscale the planned prison rebuild at Waikeria.
"If the Summit was genuinely about looking at ways to reduce crime, then National would support that. But all the talk from this Government so far has been focused on having fewer prisoners, rather than fewer victims."
Borrows said there were public misperceptions about crime and the issue was not helped by media using victims of their families to respond to evidence-based reports or proposals for reforms.
"You are never going to get an enhanced public debate if you start throwing emotion up against evidence."
Little also said public perceptions were one of the challenges for the reforms, saying there was a "retreat" to the extremes of the debate.
"That's all nonsense stuff. It's not what criminal justice reform is about. Criminal justice reform is about how the state takes action that is most effective in stopping offending and reoffending."
Little said 60 per cent of offenders were reoffending within two years of leaving prison.
"We should not be seeing that as an acceptable level of reoffending. In fact, in my view that is a failure. But we are not going to change that unless we change what we are doing."
While the Sensible Sentencing Trust itself does not have a representative on the panel, former SST member Ruth Money is on it.
Little said victims would be included in the process and he had personally met with Christie Marceau's parents for four hours to discuss the changes.
The advisory group will assess what is working and what is not, and what is happening overseas before making recommendations.
The advisory group also includes Dr Warren Young, Professor Tony Ward, Professor Tracey McIntosh, Dr Carwyn Jones and Dr Jarrod Gilbert. Further members were yet to be appointed.
One aspect of Little's proposed changes was the repeal of the "three strikes" legislation – a measure which was ruled out by NZ First.
Little described that as "a blip" and said he was certain NZ First supported reforms of the system.