(fashion) Mr Cruel's victims never saw his face. He always wore a distinctive black balaclava
The masked child killer dubbed Mr Cruel who terrified an Australian city three decades ago had previously committed sex crimes against adults - including raping an elderly nun.
New details of Mr Cruel's criminal past are revealed in a book which examines some of the country's most notorious murders and unsolved crimes.
Mr Cruel, whose identity is still unknown, assaulted at least four young girls in Melbourne in the late 1980s and early 1990s, abducting three and killing one.
Karmein Chan, a 13-year-old private schoolgirl snatched from her home after her sisters were forced into a wardrobe, was shot three times in the head.
The mystery clean freak's brazen attacks were so meticulously planned and committed in such a calculated fashion he was initially known as 'Mr Cool'.
He broke into suburban Melbourne homes at night armed with a knife and handgun, tied up parents and siblings then abducted girls as young as 11 who he held for up to 50 hours.
He forced the girls he assaulted to wash and carefully brush their teeth and fed some of them meals even while they were being abused.
None of his surviving victims ever saw Mr Cruel's face which was hidden by a chilling black balaclava with white stitching around the eyes and mouth.
No useful forensic evidence was recovered from any of his crime scenes. There were no fingerprints to compare or any trace of DNA.
The child killer dubbed Mr Cruel who terrified Australia three decades ago previously committed sex crimes against adults, including raping an elderly nun. Mr Cruel abducted at least three girls in Melbourne and is believed to have murdered Karmein Chan (pictured)
Karmein Chan's mother visited the site where her daughter Karmein's body was found a year after she was abducted from her home. Mrs Chan and her husband had made tearful public appeals for Karmein's safe return. Police believe the girl may have seen her abductor's face
Forensic anthropologist and criminologist Dr Xanthe Millett has offered a fresh perspective on Mr Cruel's offending in her latest book, Cold Case Investigations.
The book also examines cases including that of backpacker killer Ivan Milat, the disappearances of the three Beaumont children in 1966 and the presumed abduction of toddler William Tyrrell in 2014.
Mallett, who is also a television presenter and social commentator, uses her own expertise and the assistance of other experts to revisit and analyse these infamous crimes.
She concludes Mr Cruel was an 'intelligent, meticulous and callous' offender likely to have been actively involved in his community and considered by his neighbours as a 'nice guy'.
Mallett reveals in an exclusive extract of Cold Case Investigations provided to Daily Mail Australia that Mr Cruel had a more complicated pattern of offending than previously supposed.
Forensic psychologist Tim Watson-Munro, who worked on the Mr Cruel case, told Mallett he did not believe the offender had a specific attraction to prepubescent children.
Watson-Munro said investigators had asked him to profile Mr Cruel's offending, which included previous sexual assaults of adult women not known to the public.
In one of those attacks Mr Cruel had raped an elderly nun then driven her car to a bank where he used her ATM card to steal her savings.
'There were a number of other crimes involving the detention and rape of adult women,' Watson-Munro told Mallett.
This sketch of Mr Cruel's bedroom was made with the help of one of his child victims. Mr Cruel kept the first child he abducted for 18 hours and the second for 50. The last child he snatched, Karmein Chan, was found dead a year after her disappearance. She had been shot in the head
Sharon Wills (left) was the second girl abducted by Mr Cruel. Nicola Lynas (right) was the third. Sharon, 10, was released after 18 hours while Nicola, 13 was held captive for 50 hours
He suggested Mr Cruel had become desensitised to the 'extreme sadism and brutality' he inflicted upon those adult victims and turned to children to satisfy his perverted desires.
Mr Cruel came to the attention of police on August 22, 1987 when he broke into a family home at Lower Plenty, in Melbourne's north-eastern suburbs.
Once inside he tied up the parents in their bedroom, covered their eyes with surgical tape and forced them into a wardrobe.
He then blindfolded and gagged their six-year-old son, tied him to his bed and went after his 11-year-old sister.
After making the girl brush her teeth he assaulted her. He cut the phone lines and told the girl she could free her parents after she counted slowly to 100.
All up he spent about two hours in the house, even making himself a meal.
Mr Cruel next struck on December 27, 1988 when he broke into the home of John and Julie Wills and their four daughters at Ringwood.
This map from Cold Case Investigations shows the sites where Mr Cruel attacked and abducted children, where he released them and where Karmein Chan's body was dumped
Having threatened the Wills parents with a gun and tying them up with copper wire he bound their ten-year-old daughter Sharon, covered her mouth and eyes with tape and abducted her.
The next night, 18 hours after she had been snatched, Sharon was dropped from a car at nearby Bayswater High School wearing a man's shirt and green garbage bags.
The rapist known in the media as 'Mr Cruel' attacked girls as young as 11 in Melbourne in the 1980s and 1990s.
August 22, 1987, Lower Plenty: Mr Cruel broke into a house in the night, locked the parents in a wardrobe and attacked their 11-year-old daughter.
December 27, 1988, Ringwood: Broke into a house, tied up the parents and abducted their 10-year-old daughter, releasing her at a school 18 hours later.
July 3, 1990, Canterbury: Broke into a house, abducted a 13-year-old girl and drove her to another house where he kept her for 50 hours before release.
April 13, 1991 Templestowe: Broke into a house and abducted Karmein Chan, 13. Her body was found a year later.
Mr Cruel has never been identified.
Sharon told police her attacker had made her shower and brush and floss her teeth. He had kept her blindfolded throughout the ordeal and given her food while she was being assaulted.
'We can only dread what the man would have done if the girl had pulled of the blindfold and seen his face,' Detective Chief Inspector Des Johnson said at the time.
'It is that close to being a homicide.'
The next attack came 18 months later on July 3, 1990 at Canterbury. Brian and Rosemary Lynas were out for dinner with friends but their daughters Nicola, 13 and Fiona, 15, were home.
Mr Cruel broke into the Lynas house armed with a gun and a knife and threatened the sisters before bundling Nicola into a stolen rental car. He made her bring her Presbyterian Ladies College uniform.
Fifty hours after her abduction Mr Cruel dropped Nicola, blindfolded and wrapped in a blanket, at a power substation in Kew.
Nicola reported she had been made to brush her teeth and wash herself thoroughly. She had been given food and water regularly while held captive.
Her abductor had watched a press conference in which Mr Lynas pleaded for the return of his daughter and had spoken to Nicola about it.
By now police had this description of the offender: Caucasian, aged between 30 and 50, from 173 to 180 centimetres tall, of medium build with a small pot belly.
He had fair or sandy hair, spoke with an Australian accent and used old-fashioned phrases including 'bozo', 'missy' and 'worrywart'.
Police repeatedly appealed for information into the abductions of Sharon Wills, 10, Nicola Lynas, 13 and the murder of Karmein Chan, 13. No one has been arrested for any of the crimes
Nine months after Nicola's abduction Mr Cruel appeared again on April 13, 1991 at Templestowe.sonos sonos One (Gen 2) - Voice Controlled Smart Speaker with Amazon Alexa Built-in - Black read more
John and Phyllis Chan were at work in their Chinese restaurant leaving daughters Karmein, 13, Karlie, nine, and Karen, seven, at home.
Armed with a knife Mr Cruel forced Karlie and Karen into a wardrobe and disappeared into the night with Karmein. This time there would be no family reunion.
A year later, on April 9, 1992 a dog walker found Karmein's decomposing remains near a landfill site at Thomastown. She had been shot three times in the head.
Detectives believe Karmein may have seen Mr Cruel's face or recognised him in some other way, leading to him killing her.
Karmein's murder, 28 years ago, was the last attack attributed to Mr Cruel.
Over the next couple of years Taskforce Spectrum would examine 30,000 houses and eliminate 27,000 persons of interest from their inquiries.
Police investigated a theory Mr Cruel was the same man as the so-called Golden State Killer who raped and murdered young women in California before 1986. That link was ruled out and Joseph James DeAngelo (pictured) was charged in the United States with 13 murders last year
A poster featuring the faces of Sharon, Nicola and Karmein and the details of their abductions was distributed to 1.4million homes. The FBI also provided a profile.
From 2010 to 2013 police brought together under Taskforce Apollo re-examined the crimes attributed to Mr Cruel but still the identity of the offender eluded them.
Not all investigators were convinced Karmein's murder was committed by Mr Cruel.
Even the name given to the offender by a