Derek Ernest Percy was a convicted Australian serial killer and child killer, who was also a person of interest linked to the mysterious deaths of at least nine other children in the 1960s.
Early life
Percy was born on 15 September 1948 in Strathfield, New South Wales, the eldest of three sons of parents Ernest Percy and Elaine Percy. His father had been a New South Wales railway electrician before deciding to take a job with the State Electricity Commission in Victoria, and moving to Chelsea, then to Warrnambool in 1957, and to Mount Beauty, near Bright in 1961. Percy began to attract the attention of authorities in late 1964 when, as a 16 year old boy, he started stealing and wearing female underwear and mutilating dolls with razor blades and knives. In 1965, the family relocated to Khancoban in New South Wales, where he began writing down bizarre and violent sexual fantasies. In 1966, he repeated year 11, then tried year 12, but dropped out and joined the Australian navy as a naval rating in electrical mechanics in November 1967. He was posted to the aircraft carrier HMAS Melbourne in March 1968, HMAS Sydney on 1 July 1968, and HMAS Cerberusnaval base in April 1969.
Criminal investigation
Percy was arrested at Cerberus, adjacent to Crib Point on the Mornington Peninsula, south of Melbourne, for the murder of 12 year-old Yvonne Tuohy at Ski Beach, near Warneet on Westernport Bay, on 27 July 1969. At the time he abducted Tuohy at knife-point, he also tried to abduct her friend, Shane Spiller, 11, who only escaped by threatening Percy with his tomahawk. Spiller, however, was able to describe to police the abductor and his vehicle, an orange Datsun station wagon with a navy sticker on the back window. Police then went to the Cerberus base and discovered Percy washing blood off his clothes. When questioned, he denied involvement, but eventually led police to her body on Fisheries Road at Devon Meadows, some from the abduction scene. In 1970, he was found not guilty, by reason of insanity, of the murder of Tuohy, and remanded indefinitely.
Other investigations
Due to the nature of the attack, and based on documents in his possession, he also became a suspect in a number of other unsolved crimes:.
Wanda Beach case – Percy was known to be visiting his friend's grandparents in Ryde at the time, a house near to the homes of the victims. Based on Identikits, witnesses recalled seeing a young man resembling Percy talking with the girls on the train and at the beach, and he was considered a leading suspect for the murders by the police.
Beaumont case – Percy admitted to being at Glenelg Beach in Adelaide on a family trip on the day of the disappearance, but denied any involvement.
Allen Redston case – Canberra Police issued a description of a fair thin-faced teenager that they wanted to interview, and also released an Identikit image which closely resembled Percy. Percy later told police he had been in the capital, but that he was unable to remember any details.
Simon Brook case – Percy had been stationed at the Cockatoo Dry Dock on Sydney Harbour at the time, and an Identikit of the suspect who killed the three-year old was similar to the Redston suspect. A new inquest was held in 2005 with Percy as the prime suspect, but stalled due to lack of evidence.
Linda Stilwell case – In October 2014, a year after his death, he was formally ruled to have abducted and killed the seven-year-old, who disappeared while playing at the St Kilda foreshore in Melbourne on 10 August 1968. At the time, Percy had been transferred to the troop ship HMAS Sydney, and was on leave.
12-year old girl - attempted abduction while riding her bicycle near the Cerberus base. Victim identified Percy after the Tuohy incident.
He repeatedly stated, however, that he could not remember whether or not he had committed any further crimes. Detectives then started trying to piece together his movements around Australia at the time of the murders. They were aware the family often took caravan holidays during yachting regattas near beaches, that his transfers within the navy brought him close to many of the crime scenes, and knew that Percy was harbouring paedophilic and psychopathic fantasies towards children. In 2007, a cache of 35 boxes of Percy's diaries, drawings, and newspaper clippings was found in a storage unit in South Melbourne, casting further suspicion on him.
