Gardaí on television tend to be portrayed either as lovable rural lummoxes (the dreadful Brendan Gleeson film The Guard has a lot to answer for) or angry Dubliners with too much stubble. Neither caricature is accurate and credit must go to the engaging true crime series The Case I Can’t Forget (RTÉ One, Wednesday, 9.35pm) for painting the force in a more truthful light.

Each week, gardaí revisit a significant criminal investigation from their past – discussing how it affected them personally and professionally. In the final episode of the latest series, officers in Mullingar discuss a case that resulted in the first human trafficking conviction in Ireland.

At one level, it’s a story with a positive outcome. The three traffickers were found guilty, and their victims, Nigerian women forced into prostitution, were in court to see justice done. But this was, in other ways, a depressing tale. Human trafficking legislation has been on the books more than a decade, but it was only in 2021 that this first conviction was secured.

The Irish court system was also revealed to be behind the times, with victims required to be in court to give their testimony – in full view of their abusers. “They had to give evidence in court. In the UK they would never give evidence in court. It would be by video or behind a screen,” says Kevin Hyland, the UK’s first Independent Anti-Slavery Commissioner. “You wouldn’t put a victim through that.”

You can only applaud the women for speaking out and the Garda for seeing the case to its conclusion (the investigation was led by Superintendent Dermot Drea, Det Gda Niall Stack and Garda Karen Coghlan). Understandably, none of the victims appear on camera, but one does share her experiences via an actor. “They treat you like you’re not human,” she says. “I hated all of it. I hated my situation.”

The traffickers were based in Mullingar, but the women were sent all over Ireland – set up in an apartment in Cork City one week, dispatched to Leitrim the next.

“You wouldn’t have a sex trade without demand. The Irish trade is worth €180 million a year,” says Barbara Condon of Ruhama, which works with women affected by prostitution and sexual exploitation. “Huge profits are made when you sell a human being over and over again. Six to eight per cent of men buy sex.”

Not that the men in these cases were buying sex. They were paying to take advantage of women forced into acts against their will, says Dr Hayley Mulligan, an expert in gender and human rights. “It’s violent abuse they are purchasing,” she says. “Sex is very different.”

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A complicating factor is that the victims had been blackmailed through a religious ceremony in Nigeria described as ‘juju”, which left them fearing they and their families would suffer physical harm if they refused to follow their traffickers’ instructions.

The successful prosecution of the three traffickers, all based in Mullingar, is a testament to the hard work of the gardaí. But it is also an important and overdue warning that vulnerable women are being taken advantage of in horrible ways in this country every day.

“The women who gave evidence they showed extreme courage,” says Kevin Hyland in an uncomfortable coda. “We should replicate their courage by making sure this crime doesn’t get committed anywhere in Ireland.”