Michael Guider was born in the city of Melbourne, Victoria, Australia. He and his mother moved to Sydney in 1952. His mother had an unstable relationship with an army cook who was an alcoholic. A brother, Tim, was born in 1953. The two boys spent time in institutions because their mother was unstable and unable to look after them. Guider later told prison psychologists that he sexually abused his mother, his brother Tim and few of the younger boys at the boys' home.
In the 1970s Guider was charged with various offence's after setting fire to a shop owned by a woman he had had a relationship with. Guider had worked as a gardener at the Royal North Shore Hospital, and over the years had developed a keen interest in Aboriginal culture and sites around Sydney. He had earned some respect as an amateur expert on the subject and his material had been used and acknowledged in at least one published book.
The law caught up with Guider in December 1995, after he had fondled two seven-year old girls. One of the girls told her mother, who went to the police. He was subsequently arrested, and in 1996 was sentenced to 16 years' imprisonment with a non-parole period of 10 years on no less than sixty charges against eleven children. His usual modus operandi had been to babysit the children of women he knew and sedate them with the sleeping drug Temazepam. He would then molest and photograph them while they were asleep. He received a fixed term of six years and six months' imprisonment in 1999 for 11 further charges against two other children, with the judge ordering that six months of the sentence be served cumulatively.
Guider was placed in conditions of strict protection in Goulburn prison. In spite of this, he was bashed savagely on two occasions. He was admitted to the prison hospital with fractures to his right leg and hand, plus numerous abrasions. One of his ears was almost torn off. Taking time served in pre-sentence custody into account, Guider was eligible for parole in June 2014. On that occasion, his request for parole was denied, with the result that he still had approximately five years to serve.
Samantha Terese Knight was born Samantha Terese O'Meagher on the 25 March 1977. She lived at Manly with her parents, Tess Knight and Peter O'Meagher, but they divorced at an early stage. Samantha then lived with her mother in Bronte. By 1986, they were living in a block of flats in Imperial Avenue, Bondi. Samantha Knight went missing on 19 August 1986. Despite an intensive campaign, in which posters of her were displayed all over New South Wales, she was never found.
Guider eventually attracted the attention of police who were investigating the disappearance of Samantha, partly because of pressure from Denise Hofman (author of Forever Nine), who had worked with Guider on Aboriginal sites around Sydney. Freelance journalist Di Michel, who had introduced Hofman to Guider, had told Hofman how Guider had talked about Samantha Knight in a way that had sounded odd, arousing her suspicions. Michel, however, was reluctant to go to the police because she felt she would be informing on a friend. Hofman, therefore, decided she would have to go to the police herself with this information. She duly passed the information on to a detective at Castle Hill police station.
Questioned by police, Guider initially told police that he had only met Samantha Knight a couple of times over the years, but it eventually turned out that he had molested her and two other girls at a house in Raglan Street, Manly, a number of times during 1984 and 1985. After a lengthy investigation, Guider was arrested and charged with Knight's murder on 22 February 2001. On 7 June 2001, he pleaded guilty to the manslaughter of Knight. He claimed that he had drugged her the way he had always drugged his victims, but had accidentally given her a fatal overdose.
On 28 August 2002, Guider was sentenced to 17 years' imprisonment with a non-parole period of 12 years for manslaughter, to be served cumulatively with his sentence for the child sex offences. Knight's body has never been found; Guider showed no remorse, and said he could not remember what he did with her body.
Guider's statements about Knight over the years were contradictory. Initially he said he could remember nothing about what he did with her body. Later he said he had buried her in Cooper Park, in the Sydney suburb of Bellevue Hill, but had dug her up later and put her in a dumpster at the Royal Sydney Yacht Squadron, Kirribilli, where he had worked as a gardener at the time. In March 2003, he told police he had buried Knight in the grounds of the Royal Sydney Yacht Squadron. On 15 May, a dig took place there but nothing was found, in spite of a police sniffer dog reacting positively to soil from the site. The dog's handlers said the reaction was as positive as the dogs were capable of being, and were surprised that nothing was found. Police believe Samantha's remains may have been removed accidentally during the construction of a car park eighteen months after Guider buried her at the site, or that Guider himself may have removed them when he heard the site was going to be dug up.
Renee Aitken was abducted from her home at Narooma, on the south coast of New South Wales, in February 1994. She was five years old. The chief suspect was Brian James Fitzpatrick, who had done time in prison for indecent assault. Fitzpatrick died in a car crash just weeks before he was due to appear at an inquest into Renee's death.
By 2006, Denise Hofman suspected that Michael Guider may have been involved in Renee's disappearance. At the time, Guider was working just two hour's drive from Narooma, in a Canberra suburb. His mug shot was identified by a member of the Aitken family and an important witness in the case. He had clippings about Renee in his scrapbook on missing children, and these clippings came from local papers in Narooma, which implied that he had been in the area. However, police considered that there was insufficient evidence to make it worth following up on Hofman's theory. Denise Hofman drew the attention of police to a sketch by Michael Guider, which depicted a girl with a strong resemblance to Renee. Police have viewed the sketch but there were no further developments.
While in prison, Guider continued to pursue his interest in Aboriginal culture and history, writing a number of short books on the subject. These books were sent to various councils in Sydney and then held in various local libraries, as well as the State Library of New South Wales. He produced something like sixteen books varying in length from six pages to twenty-eight. He also commenced study of archeology and attained a degree in this field.
Guider was eligible for parole in June 2014, when his minimum term of eighteen years and three months was up, but it was rejected by the State Parole Authority. There were several reasons for this, including "a need for structured post-release plans."
Parole was reviewed in April 2017, but denied. He was then due for review in April 2018,but may still be kept incarcerated. One possible mechanism for this is the Emergency Detention Order, which would give the government more time. They can then seek an Interim Detention Order to keep him in prison while the court hears their application for a Continuing Detention Order. Under the latter, he could be locked up for another five years, after which the government could seek another Continuing Detention Order. Emergency Detention Orders were introduced into law in 2014 to strengthen the supervision of high-risk sex offenders and other violent offenders who present a danger of reoffending if they are released.