For a number of years, former primary school teacher Chock Soon Seng taught Chinese to primary and secondary school students as a freelance tutor.
But he had a dark secret - the 43-year-old was convicted twice for sexually abusing boys.
He was jailed for 10 months in 2010, when as a primary school teacher he tried to persuade two 13-year-old boys to let him watch them perform a sexual act. In 2014, he was sentenced to three years' jail for offences that included sexually abusing a 14-year-old boy and threatening to put his naked pictures online.
The tutor struck again, abusing two underage boys, and in April this year, he was sentenced to six strokes of the cane and eight years of corrective training for four counts of sexual penetration.
Corrective training is usually imposed on repeat offenders, without the usual one-third remission for good behaviour.
The case is the latest to throw light on the sentencing and rehabilitation regimes of sexual offenders who target children, and comes amid a report in January that showed 2,798 victims below 16, and 1,000 victims between 16 and 20 years old, were sexually assaulted from 2017 to 2019.
People who have committed serious offences, which include serious sexual offences against children, are required to undergo the mandatory supervision and aftercare support under the Mandatory Aftercare Scheme upon their release. Implemented in 2014, conditions include counselling sessions, curfews and electronic monitoring or tagging.
Prior to the regime, some offenders could have been released without being subject to additional conditions.
Ms Arvina Manoo, senior psychologist and assistant director of the sexual violence unit at the Psychological and Correctional Rehabilitation Division of Singapore Prison Service, told The Sunday Times: "Not all offenders who commit sexual acts against children present with paedophilia or mental health conditions."
While behind bars, people convicted of sexual offences against children may undergo a psychological assessment to determine their risk of reoffending and intervention needs.
The psychological intervention aims to help them address problems with interpersonal relationships, emotional regulation and negative attitudes that support sexual offending.
They may also be referred to relevant agencies in the community for further counselling and support after their release.
Dr Christopher Cheok, senior consultant and acting chief of the department of forensic psychiatry at the Institute of Mental Health (IMH), said that medication to manage sexual arousal is available to those who display paedophilic tendencies. "The use of these medications should be discussed with a doctor," he cautioned.
Ms Arvina said that some key factors that are associated with the sexual abuse of children by adults include social difficulties such as social isolation, loneliness and deviant sexual fantasies.
"Apart from individual factors, situational and environmental factors can also play a key role in sexual offending against children. Proximity or easy access to children can facilitate offending. Other factors may include the development of unhealthy beliefs about children and sex through exposure to child sexual abuse material," she added.
Dr Cheok noted that there is a range of sexual desire. "For example, a person may not be exclusively a paedophile; he may be aroused by either adolescents or adults," he added, noting that most paedophiles are male.
"A paedophile may also just have fantasies regarding pre-pubescent children without assaulting any victims. A sex offender who preys on children, on the other hand, is someone who acted on a victim and who has been caught.
"It is also important to know the level of distress experienced by the person arising from his paedophilic desires, his personal value system and his ability to control himself. For example, would he have access to a potential victim within or outside the family, and if he does, would he be able to resist preying on the child?"
Both experts addressed proximity to potential victims, which begs the question of whether repeat offenders, like Chock, should be allowed to work with children.
In April, Law and Home Affairs Minister K. Shanmugam said in a parliamentary reply that the Ministry of Home Affairs is considering whether to make it mandatory for everyone employed in sectors involving children to be screened.
"The approach taken today is to try and balance between ensuring that persons who have committed serious sexual crimes are not employed in positions which may put children at risk; and at the same time, not to add to the stigmatisation of ex-offenders and hinder their rehabilitation and reintegration," he explained.
The police have a non-public record of those convicted of serious offences, including sexual offences. The Ministry of Education (MOE) and the Ministry of Social and Family Development, for example, work closely with the police to screen prospective employees whose jobs involve children.
Under the Education Act, centres offering tuition or enrichment programmes to 10 or more students must be registered with MOE. Tutors at these centres must also be registered and declare if they have been convicted of any offence punishable with imprisonment.
Last month, Education Minister Chan Chun Sing said in a parliamentary reply that MOE will not register any applicant who has been convicted of serious offences, including sexual offences, but these regulations do not cover freelance tutors who offer private tuition outside of centres.
"As private tuition is a commercial business, we encourage parents to exercise discretion and due diligence in engaging the services of tuition and enrichment centres, as well as individual tutors," he said.
Parents told ST that while additional checks would be reassuring, this alone is insufficient and they still need to keep a close eye on their children and teach them to look out for warning signs.
Mr Edmund Lim, 44, a customer engagement manager, said that when he was looking for a private tutor for his 15-year-old son, he and his wife asked other parents for their opinions of the tutor, and searched for reviews through online forums like kiasuparents.
The class was conducted in the living room so that his son would not be left alone with the tutor.
Ms Adriana Lim Escano, 42, who runs her own retail company Abry and is the co-founder of Mums for Life, said that she would not leave any of her children alone with a tutor even if the tutor was a woman. Her four children are aged between one and 11.
"Even in primary schools, there are checks but there have still been teachers who prey on kids," she said, adding that she is cautious of anyone who interacts with her children such as school bus drivers, sports coaches and domestic workers.
Her husband, Mr Bryan Tan, 45, who is the chief executive of the Centre for Fathering and Dads for Life, said that even with a "trust mark" issued by the authorities, "we parents have to remain vigilant, be actively involved in our children's lives and establish open communication channels with them".
How psychiatrists assess paedophiles
In assessing potential paedophiles, psychiatrists probe their sexual practices and the level of distress they feel for their desires.
Dr Christopher Cheok, senior consultant and acting chief of the department of forensic psychiatry at the Institute of Mental Health (IMH), told The Sunday Times that a psychiatrist will ask, among other things, about their sexual practices and fantasies, the development of these fantasies, whether they were a victim of abuse, and the type and frequency of pornography viewing.
"It is also important to know the level of distress experienced by the person arising from his paedophilic desires, his personal value system and his ability to control himself," he said.
"A paedophile may not be distressed by his sexual attraction to pre-pubescent children. In contrast, paedophilic disorder is a psychiatric disorder which is diagnosed when a paedophile is distressed by his sexual attraction to pre-pubescent children, or has acted out his desire on a victim."
The courts have handed out stiff sentences to offenders diagnosed as paedophiles who were assessed to have a high risk of reoffending.
Most notably, recalcitrant offender Kelvin Lim Hock Hin was in 1997 jailed for 40 years for luring five boys aged between eight and 13 into having sex with him, offering them free tuition and gifts. He had been convicted in 1988 of having sex with four other boys.
The landmark case saw the Court of Appeal rule that in future cases, chronic paedophiles who are shown to be unable or unwilling to control themselves, and who target children as victims should be sentenced to life imprisonment.
In 2015, Malaysian engineer Yap Weng Wah was sentenced to 30 years' jail and the maximum 24 strokes of the cane for sexually abusing at least 31 boys aged between 11 and 15. In all but one case, he either sodomised or had oral sex with them at his rental flat, in hotel rooms and toilets at shopping centres and swimming pools.
An IMH report found that he had hebephilia - a sexual preference for children generally aged 11 to 14 - and was assessed to have a high risk of reoffending.
Tougher penalties under proposed changes to law
Penalties for sexual offences against children will be enhanced under the Criminal Law (Miscellaneous Amendments) Bill introduced by Minister of State for Home Affairs Desmond Tan in Parliament on Aug 2.
There will be longer jail terms for engaging in sexual activity in the presence of a minor and for causing a minor to view a sexual image.
The changes come after a review of the sentencing framework, which was announced by Home Affairs and Law Minister K. Shanmugam in March.
The maximum sentence for the two offences involving sexual activities or images in the presence of minors will be raised from one year to two years in jail.
The first offence involves sexual activity in the presence of a minor or showing a sexual image to a minor between the ages of 14 and 16, and the second involves similar offences relating to minors aged between 16 and 18.