A three-time upskirt offender was sentenced to six months' jail yesterday.

Chan Mun Hoe, 48, faced three counts of insulting modesty. Four other charges were taken into consideration.

The former software engineer had been placed on a Mandatory Treatment Order (MTO) in June 2013 and fined $1,500 in 1997 for committing similar offences.

Last December, he boarded a train in Tampines and stood in front of a woman who was seated. He then angled his phone to capture a video of her inner thighs.

After alighting at Paya Lebar, he followed closely behind several women at the Singapore Post Centre as they were riding the escalator or taking the stairs.

A member of the public reported Chan to the police, who arrested him and found nine upskirt videos in his handphone.

In mitigation, Chan's lawyer Low Hui Hui said the videos did not show the victims' faces and were not circulated online. He asked for a four-month sentence.

Deputy Public Prosecutor Tay Jingxi argued that Chan's reoffending showed the MTO had no effect on him. She highlighted the prevalance of upskirt cases recently and called for Chan's "consistent" law-breaking to be punished.

Agreeing, District Judge Low Wee Ping said "the handphone today has become an instrument of crime". He said if the prosecution had asked for the maximum jail term in this case, he would have seriously considered it.

Anyone convicted of insulting the modesty of a woman faces a year in jail and a fine.