A separate system for sentencing Aboriginal offenders might be the key to dealing with the disproportionate number of Indigenous people behind bars, suggests a federally commissioned study.

A stand-alone code for meting out penalties to Indigenous offenders could flow from a newly created national sentencing commission with a mandate to issue legally binding guidelines, says the research study prepared for Justice Canada.

Given the failure of past attempts to address the swelling number of incarcerated Indigenous people, "a more radical approach is clearly necessary" — especially in light of the federal Truth and Reconciliation Commission's call to eliminate overrepresentation over the next decade, the study says.

The Canadian Press used the Access to Information law to obtain a draft version of the August 2015 study Sentencing Reform: Lessons from Foreign Jurisdictions and Options for Canada. It was written by Julian Roberts, a criminology professor at the University of Oxford in England and a member of the Sentencing Council of England and Wales.

Prime Minister Justin Trudeau has asked Justice Minister Jody Wilson-Raybould to review changes to the criminal justice system over the last decade with an eye to ensuring safety of communities, getting value for public money and filling any gaps.

Among the primary goals: reduce the rate of incarceration of Indigenous Canadians.

The federal auditor general recently noted that while Indigenous people make up about three per cent of Canada's adult population, Indigenous offenders accounted for 26 per cent of all people in federal custody in 2015-16.

Problems with Canadian sentencing

Roberts cites additional problems with Canadian sentencing, including overreliance on custody relative to other Western countries, variation in sentencing outcomes, limited guidance on the role and use of victim impact statements, lack of gender-specific considerations, and increased tension between the legislature and judiciary as a result of recent mandatory sentencing provisions.

In an era in which most countries are moving towards more structured sentencing, Canada is becoming "increasingly anomalous," the study says.

It highlights the option of a national sentencing commission — possibly a version of the system in England — with guidelines that would be applicable across the country, but with flexibility to accommodate differences among provinces and territories. The commission would be a primarily judicial body with representatives including prosecutors, defence counsel, and victims and offenders advocacy groups.

"A guideline system may be the only effective way of addressing Canada's most intractable sentencing problem, namely the disproportionate numbers of Aboriginals in provincial and federal correctional institutions," the study says.

Among the specific options:

— Offer guidance regarding application of guidelines to Indigenous defendants;

— Have Parliament legislate criteria that must be fulfilled before an Indigenous offender could be imprisoned;

— Craft Aboriginal-relevant sentencing principles and avenues tailored to Indigenous communities and cultures;

— Create a separate, standalone sentencing code for Indigenous offenders.

A spokeswoman for Wilson-Raybould said while the minister is consulting widely on possible reforms, she has no position at the moment on the need for a sentencing commission.

Involving judges in the development and evolution of sentencing guidelines can help ensure success by allaying fears the scheme would compromise the courts' independence, the study stresses.

"It is unlikely that substantive sentencing reform could be implemented without the active co-operation of the judiciary."

Some parliamentarians may see a sentencing commission as an erosion of their power to legislate sentencing policy, the study acknowledges. But it says in all countries where a commission exists, Parliament has continued to legislate reforms.

The existence of an independent, primarily judicial and statutory sentencing authority might help to depoliticize the debate about sentencing policy in Canada by insulating the courts and the policy-making process from populist pressure, the study adds.

"Penal populism is a well-documented threat to informed, evidence-based sentencing reform."