A teenager carried on his rowdy behaviour despite being on bail for punching a boy.
Liao Bang Xiong, 18, robbed a foreign worker of two mobile phones.
When Liao was part of a police line-up a month later, he attacked an auxiliary police officer.
He pleaded guilty yesterday to three charges: One each of causing hurt, causing hurt while committing robbery and using criminal force on a public servant.
Two other charges will be taken into consideration during sentencing.
The court heard that on Feb 28 last year, Liao and his friends went to a McDonald's restaurant in Superbowl Jurong at about 1.45am.
There, they saw the 16-year-old victim with some of his friends.
A fight started when one of Liao's friends kept repeating the name of someone from the other group.
Liao rushed to the victim, punching him on his head, hand and back.
The victim was left with bruises on his left cheek and below both eyes, a cut below his right eye and abrasions on his left cheek.
The victim went home and his sister called the police.
Then on Jan 16 this year, while Liao was on bail for the earlier offence, he and two others - Louis Chin, 19, and Jeron Liew Wei Jie, 18 - decided to rob foreign workers.
They were walking along Upper Jurong Road when they saw Indian national Balasubramaniam Sureshkumar, 29, walking alone.
Chin pushed Mr Balasubramaniam to the ground. One of the three covered the victim's mouth while the rest punched him on the head and stomach.
Liao and Chin took Mr Balasubramaniam's mobile phones - a white Samsung and a silver Nokia - before running to a nearby block of flats.
They threw away the Nokia and later sold the Samsung for $150, which was split equally between the three. Both phones were not recovered.
Chin and Liew's cases are still pending.
Liao got into trouble again on Feb 3 at the Jurong Police Division. He was there as he was meant to be in an identification parade.
While preparing for the parade, auxiliary police officer Kow Chee Siong, 36, asked a colleague if Chin should be involved as well.
Liao then started questioning Mr Kow, who told Liao to keep silent.
When Mr Kow tried to move Liao away from the other accused persons, he pushed Mr Kow on his chest, causing him to stagger backwards.
In court yesterday, Liao, who had floppy bronze hair and glasses, kept turning towards the public gallery and smiling at a friend.
The teen's handcuffed arms were covered in tattoos, a contrast to his remand outfit of a white T-shirt and brown pants.
Liao, who in 2012 was sentenced to 18 months' probation for rioting, wrote a letter of mitigation to the judge, saying that he had made "a mistake".
Community Court Judge Lim Keng Yeow interjected, saying that it was "not appropriate" to call what he had done "a mistake".
The judge has called for a pre-sentencing report to determine if Liao is suitable for reformative training.
Liao will appear in court on April 27.
This article was first published on April 7, 2015.
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