Derek Percy was one of Australia's longest serving prisoners. He's been called 'the most evil offender in our history'.

It’s Sunday the 20th of July, 1969. 

A crisp winter's day by the water in Warneet, just over 50km southeast of Melbourne.

It’s a small seaside town, the gulls are out, the air smells of the sea and only a few shops line the sleepy street. CCTV didn’t exist yet.

The winter feels even cooler by the ocean so no fishermen are out today to brave the icy breeze.

In fact, no one's out at all except 11-year-old Shane Spiller and his childhood friend 12-year-old Yvonne Tuohy as they weave through a dirt trail and make their way towards Ski Beach to set up a picnic. 

It’s school holidays in the '60s, so the kids are out and about exploring the world unsupervised. As long as they make it home before the streetlights turned on, they are fine. 

Little did Shane and Yvonne know, they weren’t fine. 

A man has watching them from his car for a while now.

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The pair collect dried driftwood to make a little bonfire; they eat their packed snacks and eventually they pack up and head back.

Shane leads the way, but before the pair make it off the dirt trail on their way home, the man appears with a knife.

He grabs Yvonne and holds the knife to her neck; he plans to take Yvonne away, and he tells Shane to come too. 

Shane just so happened to be holding a small tomahawk that he had brought along to chop firewood, and bravely waves it at the man who backs away with Yvonne.

The young boy makes a split second decision to run away, screaming for help as he scrambles through 200 metres of coastal bushland, hearing Yvonne scream for her life behind him, screaming to not be left, screaming for him to save her.

Shane makes it to the empty roadside at the same time as the kidnapper and he sees him driving away in an Orange Datsun Station Wagon, Yvonne inside wrapped in a blanket.

Shane, knowledgeable in cars and showing wisdom ahead of his years, commits the car model to memory as well as the Royal Navy Insignia he notices stuck on the back. 

By the end of the very same day, Shane’s eyewitness account leads to the police’s speedy arrest of a man named Derek Percy. 

But it’s too late.

By the time Percy is brought in for questioning, 12-year-old Yvonne Tuohy is dead.

Shane Spiller. Image: News Corp

The police caught the murderer ‘red handed’ at the local naval base washing blood off his jeans in the laundry.

Yvonne would be the last child Percy hurt, but she was most likely far from the first.

Although he was sent to jail, there was a string of unsolved child murders throughout the '60s that share a terrifying resemblance to the brutality Percy showed when murdering Yvonne. So had the police just caught a child serial killer?

Percy showed many red flags in his youth, that if present today would have most likely led to rehabilitation before any crimes could be committed.

From the age of around 15, Percy felt compelled to write his most violent fantasies in a notebook. Specifically the horrible things he wanted to do to children were all laid out and one day his father found them, read them and destroyed them from shame. 

Percy’s father was incredibly strict and his mother was overprotective, this combined with the fact that there wasn't much education on psychological issues in the '50s. In fact there was a lot of shame surrounding mental health issues, and that saw Percy’s parents do nothing about the warning signs he showed.

So when Percy’s father found these books, he got rid of them and did nothing to help his obviously sick son.

When the neighbour caught him breaking into her house and rifling through her underwear drawer, Percy’s parents did nothing.

When he was caught by a group of boys trying on women’s underwear in the bush, they did nothing.

When Percy seemed unable to stop soiling himself well into his teens, his mother took him to the doctors but nothing came of it.

We now know that Percy suffered from a condition called coprophilia, where an individual gets sexual gratification from faeces and defecation. 

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Naturally, Percy was a loner as a child. He wasn’t close to other children, even his own brothers. He worked at his father’s petrol station until the age of 17, and despite being quite gifted at school, enrolled in the Navy as soon as he could.

His naval colleagues described him as a very organised, meticulous but private person who was unable to take a joke.

Percy was only 21 years old when he was arrested for the murder of Yvonne Tuohy.

When under observation, the police noted Percy showed a complete lack of emotion and empathy. During his interrogation Percy gave carefully crafted answers like ‘I might have been there, I can’t remember,’ to avoid any future perjury charges. 

A young local constable soon realised he had gone to high school with Percy and was sent in to use his rapport to get answers. By midnight the same day Yvonne was taken, Percy gave in and took the police to the bushes where he had attempted to dispose of the young girl’s body. 

Derek Percy reenacts murder for police Image: News Corp

There were a series of unsolved crimes against children in the 1960s - The Wanda Beach murders, The Beaumont children, Linda Stilwel and Simon Brook were just a few that had the police wondering if Percy had any involvement. 

Yvonne’s post-mortem injuries raised alarms back at the station because of how similar they were to the Brook case in Sydney 12 months prior, where a three-year-old boy that went missing in Glebe was found the next day with post-mortem injuries to his genitalia. 

When directly asked if he was involved in any of the cases, Percy brought back his evasive answer ‘I might have been there, I can’t remember.’ Police later found out that Percy was in fact stationed in Sydney at the time of the Brook boy’s murder. However they never had enough evidence to convict him. 

Percy was optimistic for decades that he would be released early from jail, but despite his positive psychological reviews stating he was no longer controlled by his fantasies, the doctors didn’t feel comfortable releasing him. This was because he never made steps to acknowledge his crimes in order to move on from them and the doctors were convinced that as soon as he was free, he would kill again. 

A chainsmoker until the end, Percy died in custody in 2013 from cancer, taking his secrets to the grave as Victoria’s longest-serving prisoner. The anguish felt by the families of the victims can’t be grasped, as many of them were holding out for some closure hoping Percy would admit to the murders before his death. 

But whatever happened to Shane Spiller, the boy who got away and the reason Percy was captured?

Spiller had an incredibly tragic life, suffering from anxiety, depression and paranoia; he would have probably been diagnosed with some form of PTSD today.

As a man, he fell into some severe substance abuse especially with alcohol and morphine.

After hearing about Percy’s psychological reviews, not realising he wasn’t going to be released, Spiller went into a tailspin absolutely terrified Percy was going to come after him. 

After two attempts on his own life, Spiller went missing in 2002 and was never seen again. The likely theory is that he overdosed somewhere. But his body has never been found and there’s no way to know for certain. 

So while he escaped Percy in 1969, Spiller’s death was ultimately still on the killer's hands.

Feature Image: News Corp/Police.

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