Nine child deaths linked to Derek Percy

Child killer Derek Ernest Percy was a suspect in the deaths and disappearances of nine children but was only put behind bars for one.

He killed 12-year-old Yvonne Tuohy in 1969 but was found not guilty on the grounds of insanity and ordered to remain in jail indefinitely.

A coroner has now found Percy abducted and killed seven-year-old Melbourne girl Linda Stilwell in 1968, 11 months before Yvonne's death.

Lawyers for Linda's mother Jean Priest had argued during her daughter's inquest that Percy was in the vicinity of other unsolved murders involving children around Australia from the 1960s.

Percy was interviewed by Victorian homicide squad detectives in 2005 and questioned extensively about Linda's disappearance and the interstate deaths, but made no admissions.

The Victorian detective who led the Stilwell cold case review identified similarities between the cases.

They included the nature of the victims' injuries, the modus operandi, geographical comparisons and identikit comparisons.

Deputy State Coroner Iain West looked at the other cases as a way of furthering his investigation into Linda's death.

A forensic pathologist identified similarities in the location and nature of the injuries inflicted and that the majority of the victims were asphyxiated.

Percy was diagnosed as having a very rare and serious form of sadistic paraphilia.

A forensic psychologist who assessed him testified that it was unlikely that Yvonne's murder was the first offence of that kind committed by Percy.

Percy was Victoria's longest serving prisoner, remaining incarcerated for 43 years until his death from natural causes in July 2013.

THE CHILD DEATHS AND DISAPPEARANCES LINKED TO DEREK ERNEST PERCY:

• 12-year-old YVONNE TUOHY, Ski Beach, Warneet, Victoria, 20 July 1969

Percy admitted killing 12-year-old Yvonne Tuohy, who he snatched from Victoria's Warneet beach on Western Port Bay.

As she walked along the beach with her friend Shane, 20-year-old Percy appeared and grabbed her, threatening to hurt her as Shane held up a tomahawk he was carrying and moved towards Percy.

Shane ran into the bush to try and get help as his friend yelled "Shane, help me", but Percy drove Yvonne away and horrifically killed her.

The girl was subjected to "appalling indignities and torture" before she died, a judge said.

Under persistent and meticulous police questioning, Percy eventually admitted to his crime, but the former naval rating was found not guilty by reason of insanity and was handed an indefinite sentence.

• Seven-year-old LINDA STILWELL, St Kilda, Melbourne, 10 August 1968

Linda Stilwell's family fought a long legal battle in an attempt to have Percy reveal what happened to the seven-year-old on the St Kilda foreshore in 1968.

Percy admitted to a former school friend and policeman Ronald Anderson he was in the area on the day.

When Mr Anderson asked Percy if he had murdered Linda Stilwell, he replied: "Possibly, I don't remember a thing about it."

Percy later denied saying that during a bedside court hearing four days before he died.

Mr West in 2009 made an interim finding that Percy was in the vicinity of Beaconsfield Parade in St Kilda on the day Linda disappeared.

But the inquest was adjourned after Mr West decided not to compel Percy to give evidence, amid concerns it would be unreliable given Percy's mental state at the time of the abduction.

Victoria's highest court overturned the decision and ordered the inquest be reconvened.

Mr West has found Percy did kill Linda.

• Three-year-old SIMON BROOK, Glebe, NSW, 18 May 1968

Three-year-old Simon Brook disappeared from his Glebe home on May 18, 1968.

His body was found the next day in nearby bushes.

Percy said during a 1969 police interview that he had driven past the spot where Simon was murdered in Glebe in 1968, on the day he died.

Asked whether he killed Simon, Percy said: "I might have, I just don't remember."

In 2005 NSW coroner John Abernethy terminated the inquest into Simon's death after just one day and referred the case to the DPP, on the basis that a jury could be satisfied that a known person committed the crime. Percy was nominated as a known person.

NSW investigators believe Percy, who was living in Sydney at the time, killed Simon.

Counsel assisting the coroner Peter Zahra SC told the Brook inquest there were "striking similarities" between the case and that of Yvonne Tuohy.

Mr Abernethy agreed, calling the two killings "substantially and relevantly similar".

"The circumstances in which they occurred are, again, substantially similar," he said.

A defence lawyer told the inquest there was no direct evidence at all linking Percy with Simon's murder.

• BEAUMONT CHILDREN, Jane, nine, Arnna, seven, and Grant, four, Glenelg Beach, Adelaide, 26 January 1966

The Beaumont case is one of the most documented in Australia with the three children, Jane, nine, Arnna, seven, and Grant, four, going missing from Glenelg Beach on Australia Day.

They left their Somerton Park home to go to the nearby beach and never returned.

Their disappearance sparked a huge police investigation, which even followed up claims from a clairvoyant about the burial site of the three children.

Percy admits he was in Adelaide at the time the children disappeared and was asked during a 1969 police interview if he killed the Beaumont children.

He told police: "I could have killed them, I don't remember a thing."

During a cold case review into Linda Stilwell's death, Percy denied being in Adelaide on January 26, 1966.

• Six-year-old ALLEN REDSTON, Curtin, ACT, 27 September 1966

Allen Redston's body was found next to a Canberra creek bed on September 28, 1966.

He had gone missing from his home in the southern suburb of Curtin the day before.

His mum had sent him to buy an ice cream for himself and his brother from the local shops.

He sent his brother home and walked to a friend's house, planning to spend the afternoon playing at the Curtin tip. He waited outside his friend's house but left after a short period of time.

Percy admitted being in Canberra holidaying with his parents some time in 1966.

• 15-year-olds CHRISTINE SHARROCK and MARIANNE SCHMIDT, Wanda Beach, Sydney, 11 January 1965

Marianne Schmidt and Christine Sharrock, both aged 15, were found beaten and stabbed to death at the Sydney's Wanda Beach in January 1965.

In 2012, NSW police said a weak DNA profile of an unknown male had been identified from a pair of jeans worn by one of the victims.

But new technology needed to be developed before a conclusive match could be made, they said.

It is believed Percy was holidaying near Wanda Beach when the teenagers were killed.

When interviewed as part of the cold case review in 2005 Percy told detectives he was probably at home in Mount Beauty on holidays when the girls died.

Mr West said there were episodes of deviant sexual behaviour exhibited by Percy in his teenage years.

"Initial fantasies escalated from an incident of indecent assault on a six-year-old girl in 1966 to his admitted abduction, killing and mutilation of Yvonne Tuohy in 1969," he said.

There was also the attempted abduction of a 12-year-old girl in Bittern on Victoria's Mornington Peninsula in 1969, when Percy was stationed at the nearby HMAS Cerberus.