That's the conclusion of a new report from the Justice Reform Initiative - backed by prominent Australians, including former governor generals, retired High Court Justices and the country's brightest medical and legal minds.

The paper, which analysed crime statistics between 2010 and 2020, uncovered trends JRI executive director Dr Mindy Sotiri says paint a damning picture of the state's justice system.

Prison populations increased by more than a third, the number of people on remand awaiting sentencing has skyrocketed, and the rate of reoffending remains stubbornly high.

"There's no way that you can look at the prison system and assess it as being successful," Dr Sotiri told AAP.

Imprisonment is the state's "default response" to crime, she says, but it is costly, doesn't deter or rehabilitate offenders, and in fact tends to drive them further into a life of crime.

Despite a decline or stabilisation in crime across the state, prison populations saw record growth in the lead up to the pandemic.

Since 2010, the number of people imprisoned in NSW has grown by 38 per cent, a trend mirrored by other Australian states but not overseas.

"Only two other countries in the world, Turkey and Colombia, have seen a greater growth in imprisonment over that decade," Dr Sotiri said.

"And the more people that we put in prison, the more people that are going to keep getting stuck into that cycle."

The report found more than two thirds of NSW's current prison population had been in jail before.

Half of people who are released come back to prison within two years.

Dr Sotiri says that statistic is no surprise when the majority of inmates are homeless upon their release, their family relationships strained or broken, their employment prospects slim, and because of the overall stigma associated with time in custody.

Prisons also costs taxpayers dearly, with $1.08 billion spent across the state in 2019-20.

But it's policy choices, not crime itself, that are "unnecessarily" funnelling more vulnerable people into the system, Dr Sotiri says.

One of those policies is tightening bail laws, something the NSW government is considering doing again after what it calls a "spate of contentious bail decisions".

Attorney General Mark Speakman in November announced the laws would be reviewed, after a Sydney drug lord led police on a 16-day fugitive hunt, and an Indigenous man was shot and killed by police while out on bail.

Dr Sotiri says she understands the need for a review, but warned against tightening bail laws.

"The people that experience the consequences tend not to be the people necessarily committing the kinds of crimes that do make headlines," she said.

An already staggering number of people are awaiting trials or sentencing in NSW prisons.

People on remand are NSW's fastest growing prison population subset, with three in 10 people in custody in NSW unsentenced. That's an increase of 10 per cent over the last decade.

NSW also keeps more people on remand for over a year than any other state or territory.

"This is not because the crimes that people are committing to getting more serious," Dr Sotiri says.

"People often end up serving more time on remand than they would have spent in custody were they to be sentenced."

The JRI report argues NSW should lead the way in reforming the justice system.

The report is supported by former Governor General Quentin Bryce, former High Court Justice and Governor General Sir William Deane, and the President of the Australian Medical Association.

It is also backed by the former NSW Director of Public Prosecutions Nicholas Cowdery, former Australia Federal Police Commissioner Mick Palmer and prominent barrister Arthur Moses.

"Both sides of politics have been engaged over many decades of in a competition to see who can be the toughest on crime, the toughest when it comes to law and order," Dr Sotiri said.

"But this has really failed us as a community."

Australian Associated Press