He had been stalking and sending sexually disturbing messages to two sisters since 2010, when the girls were of ages 7 and 11.

Tan Yao Min, who was 15 years old when he began harassing the sisters, was previously convicted of the offences in 2011 and 2017. However, this did not stop Tan, now 22, from reoffending last month after being released on 21 March this year.

Tan, a former library assistant, wrote about his fantasy of molesting the younger sister in graphic details on a piece of paper and stuck it on the unit next to the sisters’ house.

On Tuesday (24 July), Tan was sentenced to two months’ jail and ordered to serve an additional 69 days for reoffending while he was out on remission. He pleaded guilty to one count of causing alarm to the girls’ mother with the offending note.

The court heard that Tan had previously served an 18-month jail term after he was convicted in 2017 for the offences of criminal intimidation, unlawful stalking and causing alarm to the two sisters and their family members.

He was released on 21 March this year on remission – after having served two-thirds of his prison sentence – on the condition that he would not reoffend. As he was assessed to pose a continuous risk to the two sisters, he was sent directly to the Institute of Mental Health (IMH) upon his release.

An assessment done by IMH on 10 May indicated that Tan had a moderate to high risk of sexual reoffending and arrangements were made for him to be discharged to a halfway house. However, Tan reoffended while he went on home leave in June.

On 16 June, Tan applied to return to his home in Pasir Ris, which he shared with his brother, sister, two cousins and his grandparents.

The following day, Tan left his home at night with a pencil and a piece of paper on which he wrote the disturbing note and stuck it with blu-tack on the unit occupied by the sisters’ neighbours.

Calling for a two-month jail term, Deputy Public Prosecutor Yang Ziliang noted that Tan was not of unsound mind and clearly aware of his actions when he reoffended.

Tan, however, blamed the doctor at the halfway house and police officers for his latest offence.

“They tried to control my freedom, that’s why I committed the offence,” Tan, who was unrepresented, told the court. He claimed that the doctor and police officers had been harassing him, causing him to lose focus on his studies.

“I know I hurt the victim and I am willing to apologise to her. I promise that I will never do it again if the police and doctor (were to) stop harassing my life,” said Tan, who asked for a fine of less than $10,000. He also claimed that he would “change himself” and go to church.

But DPP Yang noted that Tan had also promised not to reoffend when he came before a High Court judge to appeal against his sentence in 2017.

Tan was diagnosed with autism in 2010, and found to have immature personality with recurrent conduct issues and anti-social behaviour. He was sentenced to 30 months in a juvenile home following his conviction in 2011 for mischief and wrongful confinement concerning the two sisters.

In one of the messages sent to the girl’s family members in relation to his conviction last year, he said, “I want to have sex with your elder daughter. It is because I want to make her pregnant. I also want to get AIDS. I want to rape her so that she will suffer in pain. Your daughter will not love other guy. I like to kill her and make myself suffer.”