"We need to completely re-think the way we approach crime because we're putting so much emphasis on prison when we could achieve the same result, for less money, by reducing reoffending," he told Fairfax Media. "If politicians keep demanding tougher penalties ... courts will eventually deliver them. This is what's been happening over the last 30 years. We can keep doing this for another 30 years or we can offer Australians are more rational, more considered approach." The NSW prison population hit another record in January, rising 12 per cent in a year to reach 12,121. Within three years, Australia will have more than 43,000 prisoners, costing $3.5 billion a year. Successive state and federal governments have perpetuated a "tough on crime" approach, despite crime rates falling since 2000, largely due to heroin shortages and rising incomes.

"You'd think this dramatic fall in crime would bring with it a dramatic fall in imprisonment rates and a dramatic turnaround in public attitudes towards offenders, but you'd be wrong," Dr Weatherburn said. "Having pushed the law and order merry-go-round as hard as they could for more than 15 years, politicians found to their surprise that it was hard to get off. So the tougher laws kept coming." In the paper based on decades of data, Dr Weatherburn said a 10 per cent increase in imprisonment only delivers a 1-2 per cent fall in crime. It is also vastly more expensive than rehabilitative programs like Drug Courts which are effective but have never been rolled out widely, prompting him to call for a "wholesale transformation" of the approach to rehabilitation.

Non-custodial options, like suspended sentences and periodic detentions, have failed because courts are using them as alternatives to fines and bonds, not prison. When offenders breach the orders, they end up in jail. "They're really just speed humps on the way to jail," he said. "They're not a deterrent, they don't incapacitate offenders and they don't rehabilitate them." Dr Weatherburn's five-point plan also includes giving judges the discretion to set the relationship between a maximum sentence and its non-parole period and changing the approach to community corrections order by skewing resources towards detecting breaches and making the penalties lower. But the cheapest and easiest solution was to "tone down the political rhetoric".

John Dowd, QC, former Liberal attorney general and Supreme Court judge, said politicians continually towed the same line on crime because it was "populist and easy". "The result is that magistrates and judges set heavier sentences," he said. Mr Dowd, president of prison reform advocacy group Community Justice Coalition, said he had never seen the prison system in such a bad state. He said parolees needed to be better monitored and more judges needed to be hired to stop "appalling" delays in prosecutions. Sarah Hopkins, a managing solicitor for the Aboriginal Legal Service and chair of Just Reinvest NSW, said workers in the justice system had reached "an all-time high level of frustration".

"We have this entrenched public conversation around ... the need to punish and the power of punishment to deter crime. When you look at the evidence, it simply isn't true. Harsh punishment does not deter people from committing crime," she said. Just Reinvest, a pilot project in Bourke, re-aligns money that would have been spent on the criminal justice system towards education, treatment and other services to tackle the causes of crime. "With rates of incarceration of indigenous people, it's such an urgent problem and it would be such a development if people could just start embracing a commonsense approach," she said." She said there was a myth that victims of crime want harsher punishment. "Everybody would agree what victims of crime want is that the crime doesn't happen at all." The Productivity Commission found 44.3 per cent of adult prisoners released in 2012-13 returned to prison within two years, an increase from 39.9 per cent in 2010-11. In NSW, the average cost per inmate, per day, is $237.34.

A spokeswoman for the NSW government said they would consider the contents of Dr Weatherburn's paper. "Community safety is the government's number one priority and this requires an efficient and effective justice system," she said. Graphics: Mallory Brangan