Being sentenced to preventive detention on two earlier occasions had done little to deter a diagnosed paedophile from a life of crime.
Instead, Toon Wai Mun, now 54, committed sexual offences against an underage boy with special needs, shortly after his release last year.
Yesterday, Toon was sentenced to his third preventive detention and will spend 12 years behind bars. He pleaded guilty to three counts of sexual penetration of a minor and one count of performing an obscene act on a young person.
Preventive detention, which can last seven to 20 years, is reserved for recalcitrant offenders. They must serve the full sentence, with no reduction for good behaviour.
Toon, a contractor who fixed curtains, was given his first preventive detention in 1996 for drug offences and had to spend nine years behind bars. In 2006, he was given his second preventive detention and served a 10-year sentence for criminal intimidation and causing hurt.
In February last year, the victim was sent to a home run by a charitable organisation as his mother was behind bars for drug offences and he does not know who his father is.
At the home, the then 15-year-old befriended a 17-year-old youth who was Toon's neighbour. The victim left the home in July last year to live with his grandmother, but he left three months later. He then asked the 17-year-old if he could stay with him and his family for a few days.
The older teenager knew his family would not be happy about this and told his friend that he could stay with Toon instead. He also told the victim that Toon had taken in runaways previously and housed them in his one-room rental flat.
Toon agreed to let the younger teen stay with him. At around 11pm in the flat on Nov 4 last year, the victim asked Toon to massage his legs as the boy had fallen off his bicycle earlier that day. Toon obliged.
He then performed a sexual act on the boy and asked the boy to do likewise. He committed similar offences against the teenager over the next two days, the court heard.
The victim alerted the police on Nov 7 and Toon was soon arrested.