Sydney Children’s Court was a cauldron for the future Mr Bigs of organised crime and will reopen for anew generation of younger, more violent criminals.

Graffiti, symbols and defiant words are scratched deeply into the masonry and the iron doors which held children who were destined to become the underworld criminals of the future.

Closed down 33 years ago, the Sydney Children’s Court was a hellhole for wayward juveniles from mostly impoverished backgrounds, some of whom were destined to become household names for all the wrong reasons.

Now under a renovation which has unearthed some secrets inside its walls, the court is due to reopen next year and once again decide the fates of thousands of children.

This time it will be a new generation of children committing more violent crimes at a younger age under the influence of video games, television and social media.

Lost souls: Boys exercising in the yard of the Metropolitan Boys’ Shelter, a squalid dormitory at the back of the children’s court. Picture: SuppliedSource:Supplied

A 14-year-old boy accused of stealing Lara Bingle’s Aston Martin in handcuffs at Bidura court, which has now closed to make way for the new children’s court.Source:News Limited

Teenagers outside Sydney Children's Court in Surry Hills which is being refurbished for a new generation of juvenile offenders.Source:News Corp Australia

But the products of past generations of errant boys who lived in squalid dormitories within the old court complex are still remembered — and sometimes glamorised in television series such as Underbelly, Blue Murder and Tough Nuts.

The Sydney Children’s Court alumni includes organised crime boss and illegal casino operator George Freeman, Sydney’s “Mr Big” Lenny McPherson, notorious escapee Darcy Dugan, armed robber and serial escapee, Raymond John Denning, and Russell “Mad Dog” Cox.

Freeman, McPherson and Denning are all dead and Cox, who managed to walk free from prison after many years behind bars, is living in seclusion in Queensland.

In the case of Arthur Stanley “Neddy” Smith, who graduated from the children’s court to the infamous Grafton Boys Home to become one of Australia’s greatest 20th century gangsters, he is still in jail, albeit in the aged and frail section of the NSW prison system.

Neddy Smith graduated from the children’s court and brutal boys’ homes to become a gangster, heroin dealer and is serving life for murder.Source:News Corp Australia

Flash Lennie, graduate of the children’s court to career criminal.Source:News Corp Australia

Police mugshot of ‘Mr Big’ Lennie McPherson in 1960.Source:News Corp Australia

Russell ‘Mad Dog’ Cox arrested after a daring escape would open fire on police during armed robberies.Source:News Corp Australia

A LONG HISTORY

Opened in 1911 and operating until 1983, the Sydney Children’s Court was a landmark Federation-style building designed by prominent government architect Walter Liberty Vernon in the middle of an inner city Sydney slum.

Rising imposingly above the shabby tenements and ramshackle terraces of poverty-stricken Surry Hills, the court complex housed the Metropolitan Boys’ Shelter, where children were held before their court appearances.

From early on, however, male juvenile offenders were kept in custody for weeks for minor crimes such as petty theft and truancy.

Vulnerable boys from poor backgrounds graduated to crime and passed through the Sydney Children's Court which is due to reopen.Source:News Limited

For vulnerable young boys, this added up to a social disaster.

Ray Denning ended up at the Children’s Court after a childhood which ended at the age of 11, when he watched his mother commit suicide by setting herself alight.

An alcoholic who endured beatings at the hands of Denning’s father, who was in and out of prison, she doused herself in kerosene instead of facing the prospect of her husband’s release from jail.

Denning tried to save his mother, but failed, later saying “she didn’t scream and I didn’t cry”.

When he eventually was made a ward of the state, Denning was familiar with the grimy confines of the children’s court, the Grafton Boys’ Home and other places of youth detention.

Denning graduated to armed robbery with a gun by the age of 17, and made his first attempted escape just 18 months later.

Child crim turned armed robber, Denning died aged 42 soon after his release from prison.Source:News Corp Australia

An arsenal of weapons found by police after the arrest of career criminal Raymond John Denning.Source:News Corp Australia

Denning spent all but four years of his adult life behind bars, with psychological intervention, counselling and proper youth accommodation being non-existent in that era of the court’s history.

He died aged 42 from a heroin overdose, just weeks after his release from prison.

Freeman would become known as a bookmaker who always denied his links to organised crime, but he turned to crime after his father left and then stepfather died.

Arrested, aged 12, for theft and processed at the children’s court, he served two years’ probation, after which he became a stable hand and a money hustler.

Freeman was named at three royal commissions into crime and corruption.

Despite accusations of murder, drug dealing, race-fixing, bribery and illegal gambling, he evaded serious convictions from his early 30s until his death, from an asthma attack at the age of 55.

Russell Cox, who was born Melville Peter Schnitzerling, began stealing in his childhood and graduated to armed robbery in his early 20s.

Police mug shot of criminal Darcy Dugan in the Sydney police cells in 1946 when he famously escaped a prison vehicle en route to Long Bay Jail. Picture: Sydney Living Museums.Source:Supplied

He earned the moniker “Mad Dog” from his propensity to open fire at police and bystanders during armed robberies.

He led daring escapes from jail and was eventually sentenced to life in prison for a breakout in which a prison guard was shot and wounded.

Cox sensationally escaped from Sydney’s “escape proof human zoo”, Katingal prison, and spent years on the run overseas.

It was Ray Denning who tracked Cox down, and some say that Denning was given a fatal “hot shot” of heroin as punishment for his role as a police informant.

Cox walked from Grafton jail in 2004 and now lives on the Gold Coast.

Neddy Smith was an armed robber turned heroin dealer who is serving life in prison for murder.

He never knew his father, who was a visiting American serviceman to Australia in World War II, and was sent to boys’ homes after his conviction in the children's’ court for burglary and other offences.

This 19th century boot was placed in the fireplace of the children’s court to ‘ward off evil spirits’ from young offenders. Picture: NSW Department of Justice.Source:Supplied

NSW Attorney General Gabrielle Upton with archaeologist David Marcus and a child’s boot found during restoration of the Children’s Court. Picture: NSW Attorney GeneralSource:Supplied

Smith sensationally revealed that his career as an adult criminal had been “greenlighted” by corrupt NSW Police who had given him immunity to sell heroin and murder rivals.

He is depicted in the TV show Blue Murder, which is currently in production for a sequel.

Charged with eight murders, Smith was convicted of just one, of brothel owner Harvey Jones.

Now aged 71 and suffering from Parkinson’s disease, he will die in jail.

The restoration of the heritage-listed children’s court building has unearthed some interesting object such as old glass bottles, the footings of houses and a “ritual magic” item deliberately placed in a void behind an old fireplace.

A construction worker found a child’s boot, which resident archaeologist David Marcus has added to the International Register of Concealed Shoes, kept by Northampton Museum in Britain.

The Balmoral front-lace ankle boot, a model known for being worn as “Sunday best” footwear in the 19th century, was deliberately hidden to decoy evil spirits away from the poor boys who passed through it portals.

It didn’t work.

The $38 million refurbished children’s court will try and do better when it opens next year with new courtrooms and a private room for vulnerable witnesses to give evidence via closed-circuit cameras.

The Surry Hills site will replace Bidura Children’s Court building at Glebe, which has closed.

NSW Attorney-General Gabrielle Upton said the renovated site would help vulnerable juveniles and their passage through the justice system.