SINGAPORE - Having a towel in hand appears to have triggered a repeat offender's penchant for crime, the defence said before the man was sentenced on Friday (May 14).

Defence lawyer Dhanwant Singh told the court that towels seemed to be a weakness for Isa Ahmad, 56, who committed robbery and aggravated molestation using a towel on two occasions in 2017.

On Friday, he was sentenced to 12 years of preventive detention after pleading guilty to one count each of robbery and aggravated outrage of modesty.

Preventive detention is for repeat offenders who are above 30 years old and does not offer the usual one-third remission for good behaviour.

The court heard that Isa was a housekeeper at Orchard Hotel in 2017 when he molested a guest at Hilton Hotel.

He had chanced upon his first victim, a 27-year-old Thai national, before she entered Hilton Hotel on March 12 that year. He followed her, entering a lift with her and alighting when she did.

As she was entering her room, Isa grabbed her from behind and covered her mouth with a purple towel. As they struggled, he told her he wanted to "make love" to her before pulling her by the neck towards him and kissing her on the face.

He then fled, leaving his towel behind. But he returned shortly after to ask for his towel back. When the victim called security, Isa left and went to the Hyatt Hotel nearby where he stole a white towel.

While in a lift at Tang Plaza, he saw his second victim, a 48-year-old Myanmar national. He used the white towel to cover her neck and mouth in an attempt to restrain her in the lift. He then grabbed her handbag and was able to steal her iPhone.

Isa was arrested the next day outside Orchard Hotel.

On Friday, Deputy Public Prosecutor Gregory Gan urged the court to sentence Isa to 15 years of preventive detention. He told the court how Isa had committed the offences just five months after he was released from 14 years' preventive detention in 2016 for robbery.

Mr Singh asked the court for a sentence of between 10 to 12 years of preventive detention.

He said: "The towel seems to be a weakness for him... The moment he has a towel in his hand, he seems to have something wrong with him."

However, an assessment by a psychiatrist found that he did not have any mental condition or any indication of major mental illness.

Isa's sentence was backdated to March 15, 2017, from when he had been in remand.

He could have been jailed for up to 10 years for each charge of aggravated molest and robbery.