Leaders in the ACT's youth, health, legal and community sectors have jointly penned a powerful letter urging the territory government to lift the age of criminal responsibility to 14.
They warn that if things stay the same, very young children who are imprisoned will continue being exposed to lifelong harm and even early death.
At present in all Australian jurisdictions, children as young as 10 can be arrested, hauled before courts and held in youth detention.
Aboriginal children between 10 and 13 are disproportionately affected, with the ACT locking them up at eight times the rate of their non-Indigenous peers.
Nationally, Aboriginal children account for 65 per cent of those incarcerated below the age of 14.
The Council of Attorneys-General is set to discuss the prospect of changing the age of responsibility to 14 when it meets next Monday.
In an open letter to several ACT government ministers, leading local figures have strongly backed the idea.
The letter calls on the ACT government to lead the charge by making a commitment ahead of next week's meeting to raise the age, and to use the meeting to urge other jurisdictions to follow suit.
The 20 signatories include ACT Human Rights Commissioner Helen Watchirs, Children and Young People Commissioner Jodie Griffiths-Cook, and Winnunga Nimmityjah Aboriginal Health Service chief executive Julie Tongs.
"Doctors agree that children do not have the cognitive capacity to be held criminally responsible at 10 years old," the letter says, citing the Australian Medical Association's position on the issue.
"Moreover, they have found that sending children to prison can cause them lifelong harm, increase rates of mental illness, trauma, and even lead to early death.
"We should be supporting kids to thrive in family, community and culture, not forcing them into the quicksand of the criminal legal system."
The letter notes that China and a number of European countries have legislated against locking up children under 14.
"Australia is lagging behind the rest of the world - and our children are paying the price," it says.
ACT Law Society president Chris Donohue said it was "simply unacceptable" to put such young children in prison.
"Australians should be ashamed of the number of children held in prisons around the country, and especially of the extraordinary over-representation of Aboriginal and Torres Strait Islander children in detention," he said.
"We don't have to wait for the other states and territories to do the right thing."
Ms Griffiths-Cook said the ACT was well placed to lead change, given its early investment in restorative processes and commitment to justice reinvestment.
"By criminalising children as young as 10, we are punishing children with complex needs and trauma, and disproportionately ensnaring Aboriginal and Torres Strait Islander children in the justice system," she said.
Aboriginal Legal Service NSW/ACT chief executive Karly Warner said governments were not giving children the appropriate services and opportunities to thrive.
"Aboriginal children are strong, smart and resilient but we know through our Custody Notification Service that Aboriginal children as young as 10 are targeted and are being taken into custody, at risk of being taken to a barbed wire facility, strip-searched on entry, given limited access to peers, teachers and supports, and put in a concrete cell, usually the size of a car parking spot," she said.
ACT Council of Social Service chief executive Emma Campbell said the harmful consequences of incarceration for such young children could be lifelong, and recidivism was common.
"The justice system is not rehabilitative, therapeutic or trauma-informed," Dr Campbell said.
"It does not and cannot address the needs of children. It is a community failure when children are involved in crime, and we should respond with community solutions."
Raising the age is a long-term solution, according to Marymead Child and Family Centre chief executive Camilla Rowland.
"The current age for children facing criminal charges does not reflect research on vulnerable children and the impact of involvement in the justice system on them, the context of their maturity, nor does it take into consideration complexities of vulnerable families," she said.
"Raising the age prevents inappropriate admission of children into the justice system and reduces the long-term cost to society."