Bala Kuppusamy, who has spent most of the past 20 years in prison, was also ordered to be caned 24 times. It is the third time he will be getting the maximum number of strokes allowed under the law.

The serial predator had been to prison twice for rape, in 1987 and 1993. Both times, he went back to assaulting women within weeks of his release.

In his latest crime spree, between April 27 and June 10 last year, he targeted women who were walking alone, under the cover of night.

He pummelled his victims, aged 16 to 34, into submission and demanded that they hand over their money.

In some cases, he dragged the women to secluded spots and sexually assaulted them.

Yesterday, he pleaded guilty to nine charges involving four victims - three counts of robbery with hurt, four counts of sexual assault and two counts of aggravated molestation. Six other charges were taken into consideration.

Describing Bala as a 'menace to society', Deputy Public Prosecutor Francis Ng yesterday urged the High Court to lock him away for 40 to 45 years so that 'no one else should have to suffer at his hands'.

Justice Tay Yong Kwang noted Bala's 'appalling' criminal history and agreed he should be locked away for a long time.

Speaking through a Tamil interpreter, Bala pleaded to be given another chance and vowed that he would 'turn over a new leaf' and not commit a crime 'till the day I die'.

But Justice Tay pointed to his record: three series of offences spanning more than two decades. Bala could not control himself for more than six or seven weeks despite the long periods of incarceration and the many strokes of the cane he received, said the judge. He decided on 42 years, saying that even the maximum of 20 years' preventive detention - a regime for recalcitrants with no chance of early release - would be too lenient.

Read the full story in today's edition of The Straits Times.