A loanshark runner harassed debtors by splashing paint on their doors and, in one instance, locking one family in their home with a bicycle lock.
His crime spree - the latest in a long list of previous convictions - also included robbery with hurt and causing hurt to a boy aged seven by stepping on his face.
Yesterday, Mohammad Faizal Ali, 33, was sentenced to 12 years' preventive detention and 24 strokes of the cane after admitting to eight of 24 charges.
He repeatedly asked the judge to give him one "last warning" instead of sending him to corrective training or preventive detention - regimes with no remission for good behaviour which he was found suitable for.
District Judge Shaiffudin Saruwan asked him if he had thought of his ailing mother and elderly grandmother before he committed the offences.
Faizal said he did, but added that he was desperate.
As for the robbery, he claimed he was not in charge, but was helping his co-accused.
But the judge said that there was a simple English word "no", or "tidak" in Malay, he could use.
Investigation showed that sometime in late September last year, Faizal tried to take a loan from a loanshark known as Ray, but was rejected.
Ray then offered him a job as a loanshark runner with a $100 payment for each unit harassed.
Faizal agreed as he wanted to earn "fast cash" for his personal daily expenses. He recruited Norazimah Zainudin, 36, as his lookout.
A few days after the pair began working for Ray, Faizal was offered a similar job by a loanshark known as Ah Boy, who promised him $150 for each unit harassed.
In one case, Faizal not only splashed paint and wrote graffiti on the staircase landing wall, but also padlocked the gate of the Yishun unit.
The robbery case involved Indian national Rengan Thennarasu, 27.
On Oct 1 last year, Rengan had a dispute outside a Geylang restaurant with a 25-year-old woman over money for sexual services offered.
The woman rang Norazimah, who then called Faizal, saying the victim was creating problems.
Faizal arrived and punched the victim, causing him to fall. He then took the victim's wallet, and all three fled in a taxi. They later split the contents in the wallet.
In February the same year, Faizal was at his girlfriend's home in Jurong West, when he overheard her seven-year-old son scolding his mother "stupid".
He asked the boy, who was crying, to face the wall. He pushed the child, then placed his leg on the victim's face to stop him from standing up.
Yesterday, Deputy Public Prosecutor Zhou Yihong sought at least 12 years' preventive detention for Faizal, who was found to have a high risk of offending again.
She said he had committed offences since he was a teen, and his crimes tended to get more violent through the years.
He would spend very little time in the community when he was out, before he committed another offence, she added.
He has been in and out of prison on five occasions in total, she said, the most recent being the seven years' corrective training with 24 strokes of the cane in 2006 for theft in dwelling and robbery with hurt.
This article was first published on March 24, 2015.
Get a copy of The Straits Times or go to straitstimes.com for more stories.