The case has been dealt with in the courts but for the young man's family and others, including award-winning Canberra filmmaker Sotiris Dounoukos, it still seems that the death of 26-year-old Joe Cinque has yet to be put to rest.

Singh injected him with heroin while he was already heavily sedated with Rohypnol. He lay helpless and unconscious for many hours, vomiting blood, but no call was made to an ambulance until it was too late to save him. His girlfriend's inaction was compounded by others who could have also prevented the death. The court proceedings seemed to deal inadequately with the case. Unanswered questions abound.

It was a singularly shocking event for this relatively quiet town. The photo that circulated in the media at the time showed an attractive young couple, professional and university educated, their arms around each other, mocking the claims that emerged about mutual suicide pacts and bizarre "send-off" dinners, and as reports of witness inaction emerged they were hard to square with our sense of duty of care towards others.

The case brought highly regarded author Helen Garner to Canberra to observe the court proceedings. It resulted in her true crime novel Joe Cinque's Consolation: A True Story of Death, Grief and the Law, which, like her writing in The First Stone and This House of Grief, pitches its writer and reader together head-first into morally complex terrain.

No sooner had Dounoukos finished reading Helen Garner's book than he felt the need to return to the beginning - to answer his many questions.

"The anger, melancholy and sadness that you are left with makes you return to the book and go over it again, and over the details again in the hope that you don't miss something," he says.

"The facts are stark and the interpretations contentious, and there is conflict between how the lay person looks at the facts, and how the court interprets them ... This gentle and committed young man was executed by his girlfriend.

"No matter how you cut it, you want people not to escape that fact."

Dounoukos was given the rights to Garner's book, the first and only film to have acquired them. How did the writer/director and co-writer Matt Rubenstein begin work on their adaptation? They knew they didn't want a courtroom drama with a central journalist figure. They wanted something more immediate, something that allowed the audience to take Garner's place, as the investigative presence she is in her book.

"We wanted something that allowed the audience to take her place, almost as if they were sitting in that courtroom, or sitting at that dinner table."

At the same time, "the profound questions that she raises would be our ultimate goal".

The film concentrates on the period leading up to Cinque's death, while Garner's book concentrates on the aftermath and the court trials. Still, "it was absolutely an adaptation. The world of the book, the tone of the book, except we tried to make Helen's journey, our journey."

Garner's writing has always been remarkable for the way she inserts herself into her writing and makes no bones about her views, a brave thing to do. For Dounoukos, her transparency is liberating.

Could we anticipate that Dounoukos had also inserted himself within the text of his film?

"Yeah, look, it's inescapable," he says.

"Yes, I definitely embrace that, as a fact of storytelling, an inescapable element of the construction of any narrative. Matt Rubenstein and I saw this as particularly relevant to this set of facts. You've got this storytelling happening between the characters, and one of the reasons Joe died is because people were trying to figure out what was for real, what was true, and what wasn't.

"One of the things we see in the film is the passage between stories we want to believe because they're compelling and stories we want to believe because they're convenient."

And the interpretations in law and psychiatry?

"It's interesting. … most people's instincts are that there was a great injustice. It's almost like people want to know what was wrong with her (Singh) while at the same time they look at the facts and say, no matter what it was, it was an organised execution, and the sentence wasn't enough."

Singh was found guilty of manslaughter and sentenced to 10 years' imprisonment.. She was released from prison after four years, and has recently completed a PhD.

Since Garner's exceptional book, other attempts have been made to tell Joe Cinque's story that Dounoukos is highly critical of.

"You know, the fact is that some people were turned on by the audacity and success of her plan," he says.

"Like everyone, when I read the book, I was left with a lot of questions about how the judgment came down. As much as Justice Crispin is a good judge and a fine jurist, I went straight back to page one and reread that book for more insights. And it's precisely that that motivated the making of the film.

"I wanted to articulate the question through the medium that I'm involved in and maybe to be part of a public discourse, or to provoke a public discourse, in the way that cinema can, and literature can't."

There are echoes here of a 1988 film by Errol Morris, one of the best documentaries ever, about a man wrongfully imprisoned in Texas for the death of a policeman - and it's a film Dounoukos is familiar with.

Dounoukos is a graduate in law from the Australian National University, and was studying at the same time as Singh. She was a friend of friends. He went on to study film at the Victorian College of the Arts, and has made award-winning short films.

He got to know the Cinque family well as he developed his project. In preparing them for the film that was to come into being, he explained to them that his actors would "justify and fight" for their characters. And now? "They've seen the film and, as difficult as it was, appreciated that I've made the film I set out to make which includes being very clear about what I think," he says.

What's right and wrong, despite the ambiguity and shades of grey we all have to contend with. But they're very smart people, very fair and the true victims of crime in this narrative."

Joe Cinque's Consolation is out October 13.