SINGAPORE - A mildly intellectually disabled teen was on home leave from the Singapore Boys' Home when he sexually assaulted a 10-year-old boy early last year, a court heard.

Woo Eng Loong was 17 when he performed oral sex and sexually abused the boy, who has a low IQ of 87, outside a shop at Maude Road at about 11.30am on Jan 30 last year. Woo had pleaded guilty in July 2017.

Reformative training had not been recommended for the now 19-year-old, who was jailed for seven years on Wednesday (Nov 29). District Judge May Mesenas backdated his sentence to Feb 1, 2016.

The court heard that Woo was loitering around his neighbourhood when he saw the victim playing with a cat at the playground. He approached the victim and asked if he wanted to "hang out". The victim told Woo to ask for his mother's permission.

The boy pointed towards a Housing Board block when asked where he lived. Woo then took the boy to the block, entered the lift and pressed for level 3.

He later took the victim down the stairs to a secluded area one level down , outside an empty shop.

Woo then sat on an empty trolley and sternly told the victim to stand straight. Scared, the victim complied.

Woo suddenly pulled down the victim's pants and underwear to his ankles. The victim panicked and said: "What are you doing?" Woo performed a sexual act on the terrified boy who started crying. Eventually, the boy shouted for help.

Woo then covered his mouth as the boy continued to struggle.

Woo turned the boy around to face the wall and committed the second offence, causing the victim pain. He then turned the victim once again and took off his own pants and asked the boy to do the same, but the victim pulled up his pants and underwear, grabbed his bag and ran home. The boy's father made a police report.

Pressing for at least seven years' imprisonment, Deputy Public Prosecutor Chee Ee Ling said that the protection of the public is of paramount importance. She referred to Woo's serious offences and his inability to be rehabilitated due to his low IQ, lack of familial support and his propensity to target vulnerable young males.

She told the court that the victim was young and especially vulnerable with a low average IQ of 84. The DPP also said that the offences committed by Woo were premeditated.

Woo, who has previously been convicted for theft, mischief, theft in dwelling , fraudulent possession and rash act, has also been assessed to have a moderate to high risk of re-offending, she added.

Woo's pro bono lawyer Christopher Sim said in mitigation that his client has shown remorse and comes from a poverty-stricken family. His mother and sister also have low IQ, Mr Sim told the court.

The maximum penalty for sexual assault by penetration is 20 years' jail and the offender is also liable to a fine or to caning.