A 20-year-old man who, with three others, robbed two women of $5,500 in valuables was sentenced to reformative training yesterday.

Full-time national serviceman Koh Zhi Wei was the last in the group to be dealt with. The other three - Royce Tan Wen Jun, 19, Lydia Cholris Soh Ru Hui, 18, and Chong Sheng Wang, 19 - were earlier given reformative training, too.

Another robbery charge and one of being armed with an extendable metal baton were considered during Koh's sentencing.

The court heard that on Nov 13 last year - a day before the robbery - Chong suggested that Tan, who had gambling debts, could rob prostitutes at their apartments. Chong said he had done it before.

Tan then invited Koh to join them. He also told Soh of the plan and asked if she knew anyone with a car. They decided to target prostitutes because they believed prostitutes would not go to the police.

The next day, they rented a car, bought gloves and a packet of cable ties. Tan and Koh went to a condominium in Geylang East Avenue 2 to meet freelance masseuse Lin Mei Rui, 41, while Soh and Chong waited in the car. They had earlier booked an appointment with her.

When Ms Lin opened the door at about 10.40pm, the pair barged in with batons, and told her to kneel. Just then, her flatmate, housewife Zhang Daoqing, 38, came out of her room and was told to kneel as well.

Tan tied their hands with cable ties and one person watched the victims while the other searched the unit for valuables. They made off with two mobile phones and cash totalling $5,509, which they shared with Soh and Chong.

Ms Lin reported the robbery to the police three days later.

A pre-sentencing report recommended probation for Koh, which his lawyer Josephus Tan had asked for, but the prosecution said reformative training should be imposed as there were several aggravating factors in this case. Koh was found fit to undergo reformative training.

In passing sentence, District Judge Mathew Joseph said he was mindful that Koh's young age should not be held up as a shield to protect him from taking responsibility for his actions.

The maximum penalty for robbery committed after 7pm is 14 years' jail, and no fewer than 12 strokes of the cane.