Derek Ernest Percy was a sadistic child killer who murdered at least two children, though he was only ever put on trial for one.
He was a shy but extremely intelligent boy with an IQ of 122 and an excellent student until his monstrous tendencies surfaced.
A school magazine article listed his favourite saying as ‘it depends’, perpetual occupation ‘isolating himself’, ambition ‘playboy’, probable fate ‘bachelor’, pet aversion ‘girls’.
Trouble started at 15 when he began stealing women’s underwear from clothes lines when his family lived in the small Victorian town of Mount Beauty.
The culprit was a mystery to most, but a few locals not only figured it out, but feared he was capable of much worse – even murder.
Derek Percy, 21, reenacts the murder of Yvonne Tuohy, 12, in Warneet, Victoria
A local also found a suitcase containing a blinded doll belonging to a girl living next door to Percy, and women’s clothing slashed with a knife.
There were also magazine cutouts of women in bikinis with their genital areas mutilated – the slashing patterns later matched to the bodies of children murdered in the 1960s.
Percy’s disturbed writings began in 1965 and his grades collapsed to the point where he failed his Year 11 exams and dropped out of school.
His parents once found his journal full of violent sexual fantasies, but kept it quiet and burned the evidence.
Percy’s first confirmed crime was after his family moved to the Snowy Mountains when he enticed two girls aged five and six into his caravan.
He convinced them to show him their genitals, but their parents confronted Percy’s father instead of going to the police.
Percy again flunked out of school and joined the navy in 1967, where he finished top of his class.
But police believe Percy’s murders had already begun, years before he was finally caught in July 1969.
WANDA BEACH MURDERS, January 11, 1965
Marianne Schmidt and Mary Sharrock, both 15, were found stabbed to death, mutilated and buried in sand dunes at the secluded beach near Cronulla in Sydney.
Percy was known to be on holiday in Sydney from Mount Beauty, staying with his grandmother in Ryde – where the twins got on the train headed for Cronulla and were seen talking to a teen matching Percy’s description.
Their little brother later saw them walking along the sand to the dunes with a similar youth carrying a knife and a spear, before returning alone.
Percy looked so much like a sketch of the young man made from witness descriptions that when it was released, his classmates teased him about it.
When police went through Percy’s disturbed writings, one of his stories had a ‘striking similarity’ to the Wanda Beach murders.
Marianne Schmidt and Mary Sharrock, both 15, were found stabbed to death, mutilated and buried in sand dunes at the secluded beach near Cronulla in Sydney
BEAUMONT CHILDREN ABDUCTION, January 26, 1966
One of the most infamous child abductions in Australian history is also believed to be Percy’s handiwork.
Jane, 9, Arnna, 7, and Grant, 4, caught the train from their home in Somerton Park in Adelaide to nearby Glenelg Beach.
A family friend saw them talking to a young man, and at 11.45am they bought a pie and two pasties from a bakery with a £1 note.
Since they only had coins when they left home, they must have been given it by someone else. The bakery was the last time they were ever seen.
Percy denied abducting the children when questioned before his death, but admitted to being on Gleneg Beach on the same day.
The three Beaumont siblings: Jane, 9, Arnna, 7, and Grant, 4, who disappeared on January 26, 1966
ALLEN REDSTON MURDER, September 28, 1966
Allen Geoffrey Redston, 6, was abducted as he walked to buy ice cream from his local milk bar in Canberra.
His body was found the next day hidden in reeds in Yarralumla Creek, wrapped in green floral housecoat and several pieces of carpet with a rope around his neck.
He was tied with a coarse piece of cloth with a pattern very similar to the uniform tie at Percy’s school in Mount Beauty.
Classmates years later remembered Percy wearing a homemade version of the school tie that was coarser than the genuine article.
A witness also saw a man riding a red bike with distinctive handlebars just like the one Percy was known to take on holiday with him, and a sketch of the suspect closely resembled him.
Percy said he went on holiday to Canberra, but wasn’t sure when.
Allen Geoffrey Redston, 6, was abducted as he walked to buy ice cream from his local milk bar in Canberra
SIMON BROOK MURDER, May 18, 1968
Simon Brook, 3, went missing from the front yard of his family home in Alexandra Lane in Glebe, Sydney.
His body was found dumped behind a building site, his throat cut, mouth stuffed with newspaper, and his pants pull off and his lower body mutilated.
Two Gillette razorblades were found nearby – the same brand issued to sailors at the time.
Percy was at the time stationed on HMAS Melbourne and went through Glebe travelling between the Garden Island naval base, where he lived, and Cockatoo Dry Dock where the Melbourne was undergoing a refit.
A truck driver said he saw Simon being led by the hand by a young man, a sketch of whom looked eerily like Percy, in Jubilee Park near the boy’s home.
Percy would only say he ‘could have’ killed Simon, and was in the area at the time.
A coroner recommended Percy be charged with murder after an inquest in 2005, but prosecutors decided not to.
Simon Brook, 3, went missing from the front yard of his family home in Alexandra Lane in Glebe, Sydney
LINDA STILWELL MURDER, August 10, 1968
Linda, 7, was fishing with her brother Gary, 9, before she left with three boys to Little Luna Park and then to a police station to pick up fishing rods.
But by the time the boys got to the police station, Lina was not with them.
Instead, a witness said they saw her sitting on a grassy hill near the pier on St Kilda Beach with a man wearing a jacket style often used for sailing.
When Percy was arrested, she saw a photo of him in the newspaper and was convinced he was the young man she saw with Linda.
Percy said he drove through St Kilda that day, and a coroner in 2014 ruled he abducted and murdered Linda.
Karen, Gary and Linda Stilwell a few months before Linda Stilwell was abducted in 1968
ATTEMPTED ABDUCTION, April 1, 1969
A 12-year-old girl was nearly snatched by Percy near the HMAS Cerberus naval base, 90km southeast of Melbourne, where Percy was based at the time.
After Percy was finally arrested, she identified him as her attacker.
YVONNE TUOHY MURDER, July 20, 1969
Percy was finally caught after he left a witness to his abduction of 12-year-old Yvonne in Warneet, a town near HMAS Cerberus.
The girl was walking to the beach with her friend Shane Spiller, 11, when Percy suddenly grabbed her and put a knife to her throat.
Shane brandished a tomahawk he brought along to cut driftwood, likely saving his own life.
As he ran to the road for help, he saw Percy driving Yvonne away in his orange station wagon that a sticker on the rear window.
The sticker had a Royal Australian Navy insignia, which led police to the base where they caught Percy red handed, washing blood off his clothes.
He led them to Yvonne’s strangled and mutilated body about 8km from where he kidnapped her.
Percey killed Yvonne Tuohy, 12, after abducting her on July 20, 1969. Her friend, who witnessed the kidnapping, helped police finally arrest him
Shane identified Percy in the police lineup, but was so traumatised by the whole ordeal that his life went off the rails.
Later in life he became so paranoid that he slept with a baseball bat and cut a trapdoor into his floor, fearing Percy would come for him.
He was eventually awarded $50,000 compensation in 2000, but disappeared without a trace on September 9, 2002.
Police have since speculated he was murdered for his highly publicised compensation payout.
Percy was charged with Yvonne’s murder and found not guilty by reason of insanity, and sent to the psychiatric unit of Hopkins Correctional Centre indefinitely.
He was a model prisoner, the jail’s chess champion, a stamp collector and one of the best tennis players in his section of the facility.
A prison guard described his as ‘our Hannibal Lecter’.
During much of his time in jail, Percy amassed up to $300,000 by being controversially paid $20,000 a year in military pension.
Percy was entitled to it through a loophole: Since he was found not guilty be reason of insanity he was only medically discharged from the navy.
There were fears in 1998 that he could be released due to a change in the laws, but Supreme Court judge Geoffrey Eames denied him.
‘He has demonstrated no significant remorse or anxiety, at least none which I find credible, as to the circumstances which caused him to kill,’ he said.
Percy (centre) leaves St Kilda Road Police Station in Melbourne on August 30, 2007
Percy was also denied a request for a transfer to Thomas Embling psychiatric hospital over fears the lower security would allow him to reoffend.
His next gambit was to participate in counselling in the hope it would lead to parole, but it backfired.
Leaked session notes revealed the psychiatrist was horrified at the thought of him being transferred, and didn’t consider Percy insane.
‘The most serious aspect of his personality is his sadistic fantasy life which revolves around children, their torture and mutilation,’ they read.
‘He has no motivation to curb or control the deviant sexual fantasies. I would be pessimistic about his ability to respond to any form of treatment.’
A psychiatrist at Pentridge Prison also wrote in 1984 that Percy was ‘a highly dangerous, sadistic pedophile who should never be released from safe custody’.
Another was more blunt: ‘He’s intelligent, cunning and pure evil. There is no way he is mad.’
Experts feared that if he was transferred to a mental hospital he would earn increased freedom by calculated good behaviour, and potentially kill again.
Further adding to suspicious Percy had many more victims, a trove of his disturbed writings were found in 2007 in 35 tea chests in a self-storage locker Percy rented in Melbourne and kept paying for while in jail.
They included diaries, drawings, maps, and newspaper clippings – and some of the sadistic rape, torture, and murder fantasies almost exactly resembled actual cases.
Detective Wayne Newman reopened many of the cases linked to Percy and got closer to confirming his involvement than anyone before.
In a series of bedside interviews in the last months of his life, Percy admitted to being near many of the crimes at the same time.
However, he would always insist he couldn’t remember committing any of them.
Percy died on July 23, 2013, after a battle with lung cancer, taking his secrets to the grave.