Between 1987 and 2005, Mr Jonathan Tan spent 11 of the 18 years in jail for robbery and drug-related offences.
With help from a halfway house and a volunteer, he now runs his own landscaping business, with five former offenders working for him.
Such stories highlight the success of the Yellow Ribbon Project, which aims to support former convicts in their re-integration back into society.
Over the past decade, the initiative by the Singapore Prison Service, supported by various government and community agencies under the Community Action for the Rehabilitation of Ex-offenders (Care) network, has seen its volunteer base grow to over 2,600 members, according to latest figures.
The project also has 4,200 employers showing their support for the cause through various initiatives such as hiring ex-offenders.
Events like the Yellow Ribbon Prison Run promote the Yellow Ribbon Project and create more awareness of the challenges faced by former offenders in overcoming discrimination.
More than 9,000 people have signed up for this year's run on Sept 14.
Said Mr Tan: "The community has to play a part in being willing to give ex-offenders a second chance."
The 50-year-old recalled how he struggled to re-integrate into society after serving a two-year jail sentence for robbery in 1987.
"I did not have any new friends and I could not get a proper job to support myself."
In less than a year, he was back in prison for committing another robbery and given 12 strokes of the cane.
When he was released again in 1991, he found himself mixing with gangsters again and got involved in drugs.
He was sentenced to six years' jail and given six strokes of the cane in 2001.
After his release in 2005 with remission for good behaviour, Mr Tan spent the next two years at Breakthrough Missions, a drug rehabilitation halfway house in Pasir Panjang.
There, he met Ms Lilian Loo, who was always encouraging him to turn over a new leaf.
She gave him a job at her bubble tea shop in Jurong, but he was soon meeting other drug addicts.
Ms Loo urged him to move to another halfway house.
He did. At The Helping Hand, Mr Tan learnt about gardening and landscaping.
Within a year, he became a certified botanist and landscape designer. He distributed fliers in the neighbourhood, informing residents of his services.
"I was encouraged by the many good responses that I got. But there were also times when I was turned away after the residents saw my tattoos.
"They told me that they would not let me into their houses. I learnt that if I couldn't change people's perception of me, I could at least change myself."
Two years ago, Mr Tan proposed to Ms Loo, who is divorced with five children. The couple will tie the knot in November.
"I saw how he has improved over the years, from struggling to quit drugs to riding his bicycle around the estate to earn a living cutting grass," said Ms Loo, 55, who now helps Mr Tan run his business.
"Today, he has his own business and a lorry to take him and his workers around."
She added: "He has benefited from volunteers and has since dedicated the bulk of his time to volunteerism. It's our passion for helping others that binds us together."