Inmates had been regularly beaten or sexually abused by staff. Young people were often placed in solitary confinement for so long they'd end up defecating in their cells. And drugs were so easy to get that kids who walked into the system clean would likely test positive within a matter of weeks.

It's little wonder Mr Schiraldi now holds the firm view that most juvenile jails ought to be shut down. And as for the more punitive approach the Andrews government has adopted when it comes to youth crime?

"We went down this path as a nation in the US and we've still got a long way to go to dig ourselves out of it," said Mr Schiraldi, who has been watching Victoria's progress with interest and is currently in Melbourne this week for a youth justice symposium organised by the Jesuit Social Services.

"If you could learn anything from the US, it's don't do what we did back then. It was a bad way to go - a lot of young lives were destroyed as a result of it."

It's a cautionary tale for Premier Daniel Andrews as he attempts to shape a response to a difficult policy area fraught with political danger.

After all, youth crime is a complex problem for the government these days, and after months of riots and violent offending, the Premier's approach has been to get tough: place young people into adult prison, deploy armed guards to maintain order, lay the groundwork for a new "supermax" jail.

But according to Mr Schiraldi, now a senior research fellow at Harvard Kennedy School, a rethink is needed. The US spent decades incarcerating young people in an expensive prison system rife with endemic abuse. And, not surprisingly, many young people were leaving the system far worse than when they came in, resulting in high recidivism rates, and high costs to the community.

Finally, something shifted. Cities such as New York, where Mr Schiraldi worked as a Commissioner for the Department of Probation, started focusing less on locking kids up and more on breaking the cycle of youth crime.

Large juvenile jails were shut down, and the savings were funnelled into community-based programs to keep young offenders out of the system.

Over time, the results were compelling: from 2001 to 2013, the number of youths locked up in detention centres declined by 53 per cent. New York shut down 23 juvenile facilities, California closed eight, and Texas shut down another eight.

"I was Probation Commissioner so I was able to tell my staff: don't recommend incarceration unless the kids are high-risk and high-severity. If they're in the middle, (I'd say) here are a bunch of new programs you can recommend, and the judges would agree with us about 80 per cent of the time," he said.

"So we've had the opportunity to look at what happens when you take a dramatically different, watershed approach - and the outcomes are pretty good."

Mr Schiraldi's comments come days after the government announced revised plans for a 224-bed youth jail to be built at Cherry Creek in Melbourne's west.

The government is also in the process of reviewing the entire youth justice framework, which some believe could pave the way for an even tougher approach to teen crime.

But Mr Schiraldi urged the state not to fall into the same old trap of building more jails to simply lock up more youths.

"I'm not saying you should never deprive a child of their liberty - sometimes their crimes are so serious they need to be in locked custody for our safety or theirs," he said. "But there shouldn't be these large prison-like facilities.That's really not going to get you the public safety you want, under any circumstances."