No family members were in court to support Jason Reid when he was sentenced to 11-and-a-half years in jail for reckless manslaughter and robbery. He had killed the man who had done the most for him in recent times – rescued him from heavy drug use and increasing trouble with the law in Perth, become his carer, offering him a home and job in the remote Northern Territory community of Yuendumu. He was barely 17 at the time of the killing, a juvenile in the eyes of the law.

Reid’s offending had started before he was 12, with burglary and assault, and continued throughout his adolescence. His education had been erratic, as had his living circumstances, mostly in Halls Creek. His parents, uncles, cousins were heavy drinkers; his housing overcrowded; he saw a lot of violence and was sometimes subjected to it, especially by his father. He had been drinking, using cannabis and sometimes sniffing petrol since his mid-teens; it was an uncle in Perth who introduced him to the drug ice.

By the time Reid was sentenced for manslaughter he had turned 18 and had served almost 19 months on remand in juvenile detention. Some of that time went towards a six-month sentence he had received for escaping custody.

Unless something is done about family violence “we will be just waiting for a whole new generation of children who have been harmed to come through the system”.

Nelson Inkamala was convicted for the same killing. He was just 18 at the time. The victim, Richard Berry, had been the much-loved Yuendumu pool manager. The Aboriginal and Australian flags were flown at half-mast during the community’s moving ceremony of condolence for members of his Victorian family.

Berry had also offered Inkamala a job when he arrived in Yuendumu fresh out of jail, under a suspended sentenced for stealing and attempted robbery. He had family in court for the manslaughter plea hearing and sentencing. Their presence counted towards assessment of his rehabilitation prospects as “moderate”. (Reid’s were deemed “poor”.)

However, their support had not been enough to deter Inkamala from an adolescence of escalating crime and punishment. Perhaps it had come too late or been too intermittent. His hospital records show that as an infant he was once abandoned in a telephone box, cold and wet. His father was dead, his mother a heavy drinker. As he was growing up in and around Alice Springs he had been regularly left unsupervised while adults in the family where “down at the creek” drinking. He too began smoking cannabis and drinking in his mid-teens; he too had seen a lot of violence, including beatings meted out on his mother by her partner. A cousin to whom he was close had lost his life to violence. Against the odds, Inkamala had managed to become literate and numerate, getting through school to the start of year 12.

He had served six months of the suspended sentence, part of it at the now notorious Don Dale Youth Detention Centre in Darwin, but back in Alice Springs, as the only juvenile detainee at the time, he had been held in high security in the adult prison. For two of the six months he was effectively in isolation.

The history of both young men serves as an almost textbook illustration of background factors feeding the overrepresentation of Aboriginal people in the Northern Territory’s juvenile and adult justice systems. The royal commission into child protection and youth detention in the NT now under way will no doubt hear many similar stories. Their prevalence, though, does not reduce the damage to the individuals or the damage they go on to cause.

Sue Oliver, managing judge of the NT’s Youth Justice Court, knows it all too well. She is based in Katherine and regularly travels on circuit to seven outlying communities. At the recent Indigenous Justice Conference of the Australasian Institute of Judicial Administration (AIJA), Oliver homed in on alcohol abuse, violence and neglect in Aboriginal families as critical in creating “the propensity of their children to become offenders”, underlining the desperate need for interventions and support to turn around that incredibly harmful interplay of factors.

Topping her list of concerns is the effect of chronic trauma suffered by young people exposed to family violence. The extent of it can be inferred, she argued, by looking at the exceptionally high levels of violence towards Aboriginal women at the hands of their partners.

Put that violence on a “widescreen view”, suggested Oliver, “and what we can see is that there are children in it and they are witnessing the abuse, they are hearing the screams of their mother, they are seeing the blood, they are there, in a corner, in another room, hiding in a cupboard, out in the yard.”

She also pointed to the long-term impact of violence on women’s ability to parent: they may become dependent on alcohol or drugs and be so emotionally harmed that they lack the ability to provide the physical care, direction, constraint, supervision – let alone love – that is required for effective parenting.

An improved justice system could try, through therapeutic programs, to turn around the effects of such trauma on the current cohort of youth offenders, said Oliver, but unless something is done about the bigger picture of family violence “we will be just waiting for a whole new generation of children who have been harmed to come through the system”.

Removing children from their families is no simple solution. Children in so-called “protection” are also overrepresented in the juvenile justice system. On the day of her address to the AIJA conference, Oliver had taken a census: of the 22 youths then detained in the NT, 20 were Indigenous and eight were children “under the care” of the Department of Children and Families.

The disturbing situations of four out of five teenage girls, aged 13 to 16, who came before the Supreme Court in Alice Springs earlier this year provide cases in point. In various combinations they had committed violent offences against, in the main, women and other girls – punching, kicking, pulling and dragging by the hair, beating with sticks, threatening, terrorising, robbing. Some of their victims were known to them, Aboriginal teenagers like themselves. Others were randomly met strangers, including international tourists. For four of the five, it was accepted that neglect by their families had substantially contributed to their offending. None of the four had a steady place to call home. Three of the four had started drinking, taking drugs or sniffing; the eldest had a two-year hard drug habit. Three of the four had significantly interrupted schooling. All four had come to the notice of the Department of Children and Families; two had been removed from their families from time to time.

Their difficult circumstances continued to play out as their cases progressed through the courts. With no bail support program in the NT, their utterly inadequate supervision contributed to all four committing breaches of bail offences during this time. As a result, even the youngest was sent to Don Dale, where she had spent 83 days by the time she was sentenced for her principal offences; the others had served 173 days, 77 days and 30 days.

The Supreme Court treated them mercifully with suspended sentences. The eldest, then 17, was the best off as she could live independently, and services rallied around to help with accommodation, work, and other supports. She is said to be doing well. In contrast, the care arrangements proposed for the younger three revealed a system stretched to near breaking point.

One was returned to the same family situation she had been in, the care of an aunty who moved between an outstation and a town camp; this girl has since been back in court for new offences. For another, a great-grandmother, attending court in a wheelchair, was nominated as her primary carer.

The youngest, who had attempted self-harm while on remand and was frightened of going back to jail, failed to appear for sentencing. She had been in the care of her mother, a heavy drinker who has no stable home herself and with whom she does not feel safe. Four days later the girl surrendered to police and was remanded in custody. At sentencing the court was again merciful: she left court, her sentence fully suspended, with her grandmother, to live with her – in a town camp, along with many other young relatives looked after by this stalwart woman. Time will tell whether the support the girl gets in these conditions will be enough to turn things around for her.

Her story and the stories of young people like her suggest the challenging scope of inquiry that is before the royal commission.