An alert bus commuter helped save a schoolgirl who was being molested by a man suffering from a sexual disorder called "frotteurism".
A person with this disorder gains sexual gratification by rubbing their body against a non-consenting person, usually in public.
The commuter, Mr Mohd Nordin Abdul Muthalif, 38, became suspicious when cleaner Lim Wai Sin, 53, chose to sit next to the 12-year-old girl, despite there being numerous empty seats.
When they neared the second bus stop after the Punggol interchange, she started fidgeting. Mr Mohd Nordin, who was keeping a close eye on the pair, went up to ask if she was alright. She said she was being molested.
A district court on Wednesday sentenced Lim to 10 months in jail. He had pleaded guilty to using criminal force to outrage the modesty of the primary school student.
Mr Mohd Nordin, a crane operator, told police that during the early morning bus ride on July 31, he saw the cleaner rubbing his elbow against the girl's ribcage. He then asked the bus driver to call the police.
Lim was arrested and investigations revealed that he liked to sit beside young girls on bus rides.
Assistant Public Prosecutor Puvaneswari Sandirasekaran told the court that Lim, who is single, had been jailed for six months in 2010 for committing three similar offences.
He had also been jailed between two weeks and three months for insulting the modesty of women in 1993, 2001 and 2006, she added.
District Judge Shaiffudin Saruwan said that in determining the sentence, he had considered that the cleaner suffered from frotteurism.
The judge added that Lim, who has an IQ of 58, had "mild mental retardation" and that he had rubbed the victim's ribcage and not the chest or breast areas, which would entail heavier penalties. He could have been jailed for up to five years and fined.
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