According to the study, from 2012 to 2013 Indigenous juveniles were 15 times more likely to be in the system than non-Indigenous children, but that number rose to 18 times over the last five years.
“When you compare the two rates, the overrepresentation for Indigenous kids is getting higher,” Mr. Braddock said.
Australia’s juvenile detention facilities have been under scrutiny since accusations of abuse surfaced in recent years. In 2016, the news program Four Corners broadcast footage recorded inside the centers that showed boys being stripped, sprayed with tear gas at close range and, in one case, shackled to a chair while forced to wear a hood.
Some of those facilities, including the Don Dale Youth Detention Center in Berrimah, which was closed in 2014 after a tear-gassing incident but reopened in a nearby location under the same name, are in the Northern Territory, the area with the country’s largest Aboriginal population.
The report found that the rate of supervision had decreased in every state and territory except for the Northern Territory. There, supervision has increased by 4 percent over the past five years.