SINGAPORE - An optometrist who was convicted of grievously hurting his neigbbour by pushing him down the staircase was sentenced to six months jail on Monday (Feb 6).

But Richard Boo Peng Liang, 39, now unemployed, is appealing against conviction and sentence.

He was found guilty, after a nine-day trial, of using criminal force on Mr Koh Wei Li by pushing the 60-year-old once on his chest at a staircase landing of Block 137 Yishun Ring Road at about 11.45am on Sept 3, 2015.

He was also convicted of doing a rash act to endanger life by pushing the victim down the staircase, causing Mr Koh to suffer fractures to his face and collar.

Mr Koh also had a bruise on the forehead.

He was acquitted of a third charge of pushing the victim once on the chest.

Mr Koh, now 62, had testified that the two men often argued over different things including the flower pots Mr Koh had placed at the common corridor. The two are next door neighbours on the fifth storey at the same block.

Boo had complained to the town council over the placing of the flower pots at the common corridor.

He also made reports against the victim for allegedly breaking his glass windows and CCTV cameras he had installed outside his unit.

On the day of the incident, Mr Koh was walking along the common corridor towards the lift when he saw Boo, who asked what he was looking at.

The two started arguing at the staircase landing.

Boo then pushed the victim on the shoulder, causing him to hit his back against the lift door.

The victim asked Boo why he had pushed him. Boo used his fist to block the victim's chest and they continued arguing.

The victim pointed his finger at Boo and turned to walk towards the lift but Boo pulled the back of Mr Koh's shirt collar.

This sparked another argument.

While the victim was walking towards Boo, the younger man grabbed Mr Koh's shirt with his hands and pulled it over his head. Boo then pushed the victim down the stairs.

Mr Koh landed at the staircase landing between the fourth and fifth storey.

He called his wife a short while later and the police.

Denying that he had pushed the victim, Boo said in his defence that the victim had pointed his middle finger at him a few times and challenged him to a fight.

Boo said Mr Koh became more aggressive and grabbed his shirt and pushed him. Boo claimed he used his hands to ward off the victim.

Boo also alleged that Mr Koh had slapped him. So he grabbed his shirt collar and demanded an apology.

He tried to avoid confrontation by rushing down the staircase, and dropped his glasses which were later found under Mr Koh.

Boo's lawyer A. Rajandran had sought a fine but the prosecution had asked for at least six months' jail to be imposed.

The maximum penalty for using criminal force is three months' jail and a $1,500 fine.

For causing grievous hurt by doing a rash act to endanger life, Boo could have been jailed for up to four years and/or fined up to $10,000.