For Douglas, 55, an unexpected outcome of serving time behind bars has been a chance to hone his parenting skills.

He and some other prisoners were taught skills such as how to communicate and reconnect with their children during a programme to boost family ties. Such bonds can come under great strain as a result of an inmate's wrongdoings and neglect of family duties.

For Douglas, being a good father was, perhaps, far from his mind when the former manager became hooked on casino gambling.

His addiction drove him to commit a criminal breach of trust and he ended up with a jail sentence of 12 years.

Douglas (not his real name) said: "I will regret it for the rest of my life. I was not there for my family and I have missed all of my daughter's growing-up years."

When he was jailed, his only daughter was five years old.

She is now 11, misses him dearly but does not know what he did wrong. She knows, however, that having daddy behind bars is something shameful, something she should keep from her friends.

His wife has stood by him and faithfully takes their daughter to visit him monthly. When asked how she is affected by his incarceration, her tears spoke volumes.

I met Douglas and his family at the Tanah Merah Prison two Saturdays ago, when the Singapore Prison Service (SPS) allowed The Straits Times to be present during a special visit to celebrate Children's Day and the end of the Family Care programme run by Focus on the Family Singapore, a charity.

That day, inmates were allowed an open visit when they could hug and hold their loved ones. At other times, they are separated by a glass panel during visits.

Douglas said: "To be able to hug and touch my daughter is very important, to reassure her that daddy is still alive."

During the session, which lasted four hours, I saw how convicts became fathers, husbands and sons once again.

One man, serving a seven-year term for drug offences, was finally able to carry his youngest son for the first time. The boy was just a month old when he was jailed. The son is now three.

Another man, also jailed for drug offences, was super attentive to his 93-year-old, wheelchair-bound grandmother who had raised him. It could well be the last time he sees her.

Others have not seen their children for up to four years, facilitators of the programme said. Their spouses were either too busy to take the children to visit, or had given up on them.

As Douglas said: "I have seen so many inmates who were abandoned by their families. I also have this fear of being abandoned. If nobody cares for me, what is there to live for? When I'm released, I will think twice about doing anything (wrong) because of my family."

The fractured ties were evident from the awkwardness of some interactions. A few children remained aloof, and among the fathers, some did not know what to do or say to their children.

But for most, there were lots of hugs and catching up to do.

And the tears flowed freely when it was time to part.

A little girl cried silently, fat tears streaming down her face; a young boy kept calling for his daddy as the inmates were led back to their cells.

I'm not one given easily to tears, but it was hard to hold the waterworks back that day.

When the visit ended, the toll of crime and addiction on its invisible victims - the heartache and suffering experienced by the convicts' loved ones - sucked the air out of the room.

Research has shown that family support is a key factor in preventing inmates from reoffending. Prisons overseas have been running parenting and family-bonding programmes to this end.

In Singapore, about one in four inmates released in 2014 committed another offence within two years of leaving jail.

British researchers have found through large-scale longitudinal studies that prisoners who experienced improved family relations are significantly less likely to reoffend, more likely to find work and to stop their drug habit.

It is not rocket science, but strong family ties do motivate the offender to change for the better. But, without practical support like housing and financial help from loved ones, there is a higher chance the former convict will go back to his old network and criminal ways.

That is why the SPS has been working with social-service agencies to run programmes to help inmates build stronger bonds with their families and to address the various issues they or their families face.

For example, the Singapore Children's Society has been running Project Relate in prison since 2014 to help inmates communicate with their loved ones. Its social workers also help inmates' children and other family members to cope.

Its senior social worker, Mr Fang Xin Wei, shared the example of a relationship that healed with some help.

A drug offender was estranged from his teenage daughter, whom he had physically abused.

Social workers worked with him on his issues for three months before he decided to mend ties with his daughter. He is illiterate and social workers helped him put his thoughts onto paper.

Mr Fang said : "During the visit, he broke down when he asked his daughter to forgive his mistakes. She agreed and they hugged each other. Three months later (when social workers checked with him), he said their relationship had improved."

There are thousands of children here with a parent in jail. As of December last year, there were about 1,100 men and women inmates with children under the age of 16. One worry is that these children are more likely to go astray given that one parent - or both - is in jail and there may be no one to care for or guide them.

Research has shown that the odds of offending for children with criminal parents are, on average, 2 1/2 times higher than for those whose parents are not offenders.

The authorities have said they want to focus more on helping inmates' children and to reduce inter-generational offending.

In the past decade, SPS and its partners have made great strides in helping prisoners find jobs after their release. Being gainfully employed and occupied is one key plank of rehabilitation. Getting the family to support the inmate is another. I'm so glad that the SPS is stepping up its efforts for the latter in recent years.

Leaving the Tanah Merah Prison, I spied a mural on a prison wall. The markings appeared to be gibberish, until I read them in a mirror mounted on a facing wall and the phrase "awakening hope" emerged.

The lives of many inmates may seem nothing more than gibberish right now, but there is hope that with the right help, they can turn their lives - and those of their families - around.