WHEN BLESSINGTON disembarked from a train at Sydney's Central Station in early September, 1988, he had little money and no plans. Scott Agius introduced him to a bunch of hardened street kids, including a 16-year-old with a long criminal history, Matthew Elliott, and a 15-year-old thug called Wayne Wilmot. The teens boasted that they led the most feared gang in Sydney and invited him to their squat in Flemington, in Sydney's inner west.

Blessington immediately impressed with his skills at pilfering food, alcohol and cigarettes and his ability to use his fists. While giving boxing tutorials, Blessington landed a punch full flush on the face on another youth, Wayne Purchase. The blood on Purchase's face set off Elliott, high on amphetamines, who started slamming Purchase with a hollow sledgehammer.

Elliott urged Blessington to do the same. 'It was absolutely dreadful,' Blessington recalls. 'We hit him with everything we had. I thought we'd killed him.' Purchase survived, but by the time the police arrived, the youths had already done a runner. 'I didn't feel no remorse, but,' Blessington adds. 'What we did next to Ms Balding ''

His voice trails off. His body slumps and visibly shudders as he returns to the events of that Thursday afternoon in September all those years ago, when with Wilmot and Elliott, he met up with a bunch of vagrants at Central Station, including an intellectually handicapped 15-year-old girl, Carol Ann Arrow and an older man known as 'Shorty'.

At Central, according to a police confession from Stephen 'Shorty' Jamieson, Elliott and Wilmot would cravenly suggest, 'How about we go and get a sheila and rape her?' It was a claim that would later become one of Australia's most infamous crime headlines, suggesting that Balding's abduction was a premeditated 'thrill kill'.

I ask Blessington if the rape was planned. He looks at me and firmly replies, 'No, the plan was to steal a car.' A pause. 'No one said, 'Let's rape a girl' at the train station ' Jamo [Jamieson] wasn't even there.'

(In a baffling and bizarre feature of the case, Blessington and the other co-accused all insisted after their arrests that Jamieson ' 22 at the time, with an IQ of 65 ' wasn't with them. They identified another homeless man, Mark 'Shorty' Wells, as their accomplice. Wells, a schizophrenic and self-described Satanist, was tracked down in Brisbane more than a year after the murder. In court, he said that the reason he'd known certain details of the crime was because of a dream conjured during a s'ance. Wells was never charged. In 2006, Carol Ann Arrow reportedly said Jamieson was present. Jamieson, also jailed for life without parole, maintains his innocence and says his police confession was coerced.)

The gang spent the rest of the day riding the train network, drinking a bottle of rum stolen by Blessington from a liquor shop, yelling at school children and flashing a copy of Penthouse magazine at passengers. Blessington tells me he had begun taking 'speed pills' supplied by Elliott.

As dusk fell, they got off at Sutherland station, in Sydney's south, and found an unlocked car in the car park, but couldn't start the ignition. Elliott, the ringleader, suggested they instead follow a woman to her car, snatch her keys and drive off. Their first intended victim, Kristine Mobberley, shut the car door fast enough to escape, driving straight to the local police station. Disastrously, the cops went to a car park on the other side of the train station.

Balding was next: as she approached her Holden Gemini, Blessington asked her for a cigarette. Upon being rebuffed, he pulled out a knife and forced her into the back seat; Elliott took the wheel, driving west along the F4 freeway. At some point, Elliott moved from the front seat to the back and raped Balding, while Wilmot drove, with Arrow also upfront. They pulled off the road at Minchinbury, in Sydney's west.

'[Elliott] said, 'Bronson, have a go '' So I got out and raped her, too,' Blessington recalls.

Elliott started panicking that Balding would identify them. With Blessington's help, he pushed the terrified woman through fencing lining the highway into a paddock. 'I took her legs, Elliott took her shoulders,' recalls Blessington. 'The idea was we would tie her up and leave her there.' But then, 'our feet started sinking in the mud. We saw there was a dam and Matthew [Elliott] said, 'Let's drown her.' '

Blessington held Balding under the water while Elliott punched her stomach. 'He did it so she would swallow water and die quickly,' he says.

I ask Blessington what was going through his mind. 'There was no rage or anything inside me. It was like I was outside myself. I just felt ' nothing.'

After stealing Balding's jewellery and ATM card (they had forced her to give them her PIN), they drove to nearby Mount Druitt shopping centre, withdrew cash and abandoned the car. They returned to the city and, in Hyde Park, boasted of the murder to two girls. But a day later, suddenly gripped by the enormity of the crime they had committed, Blessington and Elliott drove another stolen car to western Sydney's Cobham youth detention centre.

They found a youth worker whom Elliott trusted and confessed to the beating of Wayne Purchase. Police were called in. The next day the pair admitted, unprompted, that they knew that Janine Balding ' at that stage reported missing ' had been raped and murdered, but insisted they did not participate. (Elliott had told Blessington to blame Scott Agius, but Agius had left the group after the beating of Purchase and tried to convince Blessington to do likewise. Agius also had an iron-clad alibi.)

The confession was damning enough to raise deep suspicions among police that they were more seriously involved. The pair took police to the dam where Balding's body lay half-submerged. 'I remember, when they took me to the crime scene, all I could think was, 'I can't believe this is a dead body,' ' says Blessington.

'Why was that all I could think about? I mean, I had killed her. But all I could think about was, 'So this is what a dead body looks like.' '

Over a coffee at the beachside Sydney suburb of Coogee, I catch up with Blessington's former lawyer (now a retired District Court judge) Kevin Coorey, who, during two trials over two years, was

at the epicentre of a media firestorm surrounding the case.

Janine Balding was a vibrant young woman from Wagga Wagga who had come to Sydney to work as a bank clerk. She had already bought a home on the NSW Central Coast with her fianc', with plans to start a family. The end of a young life full of such promise in such violent circumstances revolted the public, especially when it became defined by Jamieson's chilling confession and ape-like appearance, the result of foetal alcohol syndrome.

What's more, Balding's abduction, rape and murder bore disturbing similarities to the infamous Anita Cobby slaying, which had happened just four kilometres away and only two years earlier. Cobby, a nurse and beauty pageant winner, was kidnapped by a group of five men as she walked home from Blacktown train station, bundled into a car, battered and gang-raped, her body mutilated before she was finally killed.

I ask Coorey why he didn't submit a defence of diminished responsibility, given Blessington's youth and mental deficiencies: after Blessington's arrest, a court-appointed psychiatrist said he suffered from a 'conduct disorder of adolescence [that] fits the criteria for a defence of diminished responsibility', a formally recognised mental illness.

In his damning 'never to be released' sentencing judgment, Justice Peter Newman pointedly noted that the psychiatrist's report was never raised by Blessington's legal counsel.

'You can't run that defence when you are pleading not guilty,' explains Coorey. 'It's a contradiction.'

Blessington paid a heavy price for his perjury, denying himself a custodial sentence of less than 10 years if the diminished responsibility defence had succeeded, as many believe it would have.

During the trial, Blessington was 'very quiet', Coorey recalls. 'He hardly ever spoke.' He was a 'good head' shorter than his co-accused Elliott, barely 150 centimetres tall and 45 kilograms. 'Bronson looked like a child, and that was the hard part. It was hard to comprehend.'

The public, too, had difficulty accepting that teenagers could commit such heinous crimes, which are not as uncommon as you might like to think. According to the most recent figures produced by the Australian Institute of Criminology, there were 83 youths under 18 charged with homicide ' mostly murders ' in the five years to 2012, or about 16 each year. Of those 83, 11 were aged 14 or younger, an average of slightly more than two per year.

In most cases, such juvenile homicide trials are conducted away from the scrutiny of the media. The Balding trials could not have been more different.

As the hearings were held, Janine's mother Beverley (who died in 2013) led a high-profile campaign for the reintroduction of the death penalty. When the guilty verdict was handed down by a jury, the applause from the public galleries was thunderous, recalls Coorey. 'I've never seen anything like it.'

In sentencing, Justice Newman said Blessington was extremely young, had a 'trivial' criminal record ' just the offence for the stolen sunglasses ' and good prospects for rehabilitation. Nonetheless, the crime was 'so grave', a life sentence was appropriate for him, as well as Elliott and Jamieson. (Wilmot and Arrow were convicted as accessories to murder. Wilmot served seven-and-a-half years before being paroled, Arrow was released on a good behaviour bond.)

Newman's added recommendation that 'none of the prisoners [handed life terms] should ever be released' captured the headlines but carried no legal force. At that time, a prisoner given life had the right to have their sentence assessed and possibly downgraded after eight years in jail.

It was this prospect of successful appeals that prompted the NSW government to introduce the three pieces of retrospective legislation, at least one of which was directed solely at Blessington. Under the changes, Blessington is only eligible for release if he is on the verge of death or profoundly physically or mentally incapacitated.

Such laws mean that Blessington has been subjected to a penalty that did not exist at the time he carried out his crimes. His sentence, the United Nations ruled last year, broke international treaties that Australia has ratified, among them the Convention on the Rights of the Child.