Jail, fine for man who damaged HDB flat windows by firing ball bearings with air guns he made from scratch
The court heard that Lee Keng Hee decided to make his own air gun after buying a Nerf brand toy gun.
- Lee Keng Hee used discarded scrap metal from his workplace and watched YouTube videos to make air guns
- He had wanted to recreate the firing mechanism of Nerf brand toy guns but failed
- He began firing at trees close to his flat, then moved to shooting at other nearby public housing blocks
- Two fellow residents called the police last year over cracks in their windows
SINGAPORE — After coming across a Nerf brand toy gun in a mall, Lee Keng Hee bought it to study its firing mechanism and make one of his own.
When he failed to do so, he decided to make air guns that were powerful enough to fire steel ball bearings instead of the soft plastic pellets fired by the toy gun.
The sheet-metal worker studied tutorials on YouTube and used discarded scrap metal from his workplace to fashion the air guns.
He fired at nearby trees and other public housing blocks up to 77m from his Jurong West flat, perfecting his craft over the next few months.
But in April last year, he was nabbed when two other flat owners discovered suspicious cracks in their windows and called the police.
Lee, now aged 64, was sentenced to 18 weeks’ jail and a fine of S$2,000 on Wednesday (Dec 16). It was the first prosecution of air gun manufacturing in Singapore.
The Singaporean pleaded guilty to one charge each of manufacturing arms without a licence and committing rash acts that endangered the lives or personal safety of others.
District Judge Christopher Goh considered two other charges of possessing arms and committing mischief for sentencing.
Lee’s nine victims all lived at Block 453 and Block 536, Jurong West Street 42 — located within 100m of Lee's flat.
STUDIED TUTORIALS ONLINE
The court heard that Lee came across the Nerf gun in 2017 at Eastpoint mall in Simei.
When he tried to reverse-engineer its firing mechanism — which makes use of compressed air to propel foam bullets — and make his own air gun, he was unsuccessful.
He then decided to make his own more powerful air gun, using metal rather than polyvinyl chloride (PVC), a synthetic plastic polymer. He was concerned that PVC was not stable enough to withstand the higher pressure required to fire steel ball bearings.
He began studying air gun-making tutorials online. A forensic examiner later discovered 338 pieces of air gun-related web history content on his desktop computer.
He took home scrap metal pieces from his company’s workshop, cutting and drilling them to build component parts such as trigger systems and barrels for the air guns.
In late 2017, while building his first one, he ran into difficulties with the mechanism. He then constructed a second one using a new design idea and completed both around mid-2018.
He first used 6mm ball bearings to test the air guns at home, using a cardboard box as target practice. While he had also bought bigger 8mm ball bearings, he found them unsuitable for the air guns.
Both were able to fire the pellets but he considered the first air gun a failure because its shooting range was only about 1m. The second one had a longer range and the pellets could easily penetrate the cardboard.
From then on, he began shooting at nearby trees from his bedroom window and was able to hit them.
SHOT AT LEAST 200 BALL BEARINGS
When the second air gun malfunctioned after several uses, Lee decided to make a new and improved one with better power and consistency.
He also constructed it with a bigger air chamber to fire more ball bearings in one go.
He finished building his third air gun in October 2018.
Soon, he moved to shooting at nearby Housing and Development Board (HDB) flats from his kitchen window to determine the range of his new air gun.
He continued using Block 453 as target practice until April last year, shooting at least 200 6mm ball bearings in total. He did it from home because he knew he could be liable for a criminal offence if he was found with an air gun while outside.
He usually did it out of sight of his wife, son and cousin-in-law, who all lived with him.
On April 3 last year, someone called the police after hearing a sound and spotting a crack at his bedroom window.
The police conducted extensive door-to-door enquiries at the nearby blocks. At 4am the next day, they knocked on Lee’s door, discovering an air gun and component parts in his home.
After the police announced his arrest, several others filed reports over similar damage to their windows.
Lee admitted to shooting at trees and HDB blocks despite knowing this could damage windows.
VOLUNTARILY MADE RESTITUTION
Deputy Public Prosecutor Regina Lim sought four months and six weeks’ jail, as well as a fine.
She noted that the air guns were capable of cracking glass more than 77m away and could cause painful injuries if the ball bearings struck a person. Lee had committed his offences with a “high degree of persistence”, she added.
Lee’s lawyer, Mr Favian Kang from Peter Low & Choo, asked for four months’ jail instead.
In mitigation, he told the court that Lee voluntarily sold off jewellery from his late mother to make restitution to his victims.
He quit his job in September to face criminal proceedings but at the time, the prosecution asked for more time to prepare their submissions, Mr Kang added. This left him jobless in the interim and he “suffered some prejudice” because of that, the lawyer argued in seeking a lower sentence.
DPP Lim apologised for the delay but said that the duration was “not too protracted”.
For arms manufacturing, Lee could have been jailed up to three years and fined up to S$10,000.
For committing rash acts endangering life, he could have been jailed up to six months or fined up to S$2,500, or both.
