Police officers would become prosecutor and judge, dispensing on-the-spot punishments for minor crimes under plans to turn patrol cars into "mobile stations".

The proposal - an attempt to reduce costs and manpower, save time and free up police stations and courts - is one recommendation to be presented to Government in the police Fit for the Future project.

Deputy Commissioner Rob Pope said police hoped to create patrol cars equipped with mobile fingerprinting devices and digital equipment on which officers could dictate or type statements instead of writing them.

This would enable them to process and punish criminals on the spot.

The idea has support from Auckland defence lawyer Peter Williams, QC, who said the proposal could save defendants time and the embarrassment of turning up to court.

Mr Williams said in other countries where police have these powers, they often get in touch with social agencies. He said rather than offenders just being processed through court, their underlying problems - such as alcohol and drug addiction - are addressed.

He said that would save money and, more importantly, address underlying causes of crime.

"On the other hand, it places a huge responsibility on police to act in a fair and proper way and not to abuse their powers," Mr Williams said.

He said giving police the power to prosecute and judge could be open to abuse but only time would tell.

Mr Pope said police were still working out what type of offending the plan would cover, but it would probably be crimes prosecuted under the Summary Offences Act, which included disorderly behaviour, vandalism, tagging and indecent exposure.

It would mean those involved would not have to be processed through the lengthy justice system.

About 120,000 arrested people a year now go through the courts.

"It will be someone who is not a danger to themselves or other people," Mr Pope said.

"We're not going to deal with aggravated robberies or that type of thing on the street."

Police had been considering the ideas for a few years but the recession had "accelerated the thinking" and the Government had this year asked for a report on future policing and ways money used on current projects could be reinvested.

"What the Government is asking for, quite rightly, is it getting value for money in police services - are we providing the public with what they expect," Mr Pope said.

Police were still working on how the proposals could be implemented.

It was not known how long it would take to complete the report, but police were treating the matter with urgency.

Senior Auckland criminal lawyer Gary Gotlieb said the system would be "judge and jury by the police".

If a person decided to accept the charges on the street rather than defend them in court it could "come back to bite them on the backside".

"The person on the night might pragmatically say, 'Well I just want to get rid of it' and then afterwards say, 'Hello, it wasn't me, it was someone else that was doing it and I'm putting my hand up because I want to go to America and because I've got a conviction like this I can't go'."

Some police in the United Kingdom and the United States carry portable fingerprinting tools in patrol cars and Mr Gotleib said he'd heard of some areas which had decriminalised some offences - such as possession of cannabis - so police on the beat could punish a person by serving them with a fine rather than charging them.

A system under which victims or witnesses of crime can text or email to report the incident is also recommended in the report.

The Department of Corrections is already considering having criminals appear in court through a video link to cut transport costs and speed the justice system.
Mr Pope said police would be also recommending the process in their report to the Government.

Instant justice

Officers able to charge and deal with minor offences on the spot.

Patrol cars with mobile fingerprinting devices and digital equipment to process offenders from their vehicles.

Victims/witnesses reporting crimes by texts or email.

Prisoners appearing in court via video link.