Wellington barrister Greg King is suggesting changes to the court system which he says would give better support to offenders and reduce the prison population.
Mr King has spent two months in the United States on an Eisenhower Fellowship looking at the justice system there.
He says few prisoners come out of jail better people than when they went in, and are often battling significant problems including mental health issues and alcohol and drug addiction.
Mr King says a management court model, similar to those he saw in the US, would involve welfare and other agencies working more closely with the courts to address criminals' wider needs.
Judges would have continuing contact with offenders to monitor their compliance with drug and other prohibitions, which Mr King said could lead to criminals being released from prison earlier.
"They can be released safely, they are under oversight, they are under management and they don't present the risk to the public, because of various types of technologies that can be employed to minimise that."
Mr King says the model he is suggesting would not replace prison for serious offenders, but for those who do not have to go to prison can be dealt with in the community in a way that manages punishment and focuses on rehabilitation.
Garth McVicar of the Sensible Sentencing Trust says there could be some advantage for victims in keeping offenders out of jail, because it would mean they could keep working and be in a better position to pay reparation.
He is also impressed with the management court's use of GPS monitoring to keep track of offenders once they are returned to the community.