Victoria Police is set to announce a one million dollar reward for information that finally solves the case of Maria James, who was murdered in the back of her bookshop 44 years ago. And for the first time in seven years of investigating this case, police grant an interview to Rachael Brown.

A Victorian Coroner has failed to name a killer in the 1980 cold case of Maria James. Her sons are devastated. But there's still hope, in leads yet to be chased by police.

The new coronial inquest into the murder of Maria James has wrapped up. Will the Coroner be able to name her killer? And of the police exhibits that haven't disappeared, what DNA testing can be done? This episode nears us closer to the end of the James brothers' 41-year-fight for answers for their mum.

The discovery of a police exhibit - thought to be missing for around three decades - could finally help unmask the killer in the 1980 cold case of Maria James.

The Royal Commission has released its final report into defence lawyer turned police informer Nicola Gobbo.

We reveal the story of Nicola Gobbo's audacious bid to return to Australia.

Everything unravels, for Nicola Gobbo and Victoria Police. Their secret is out.

Nicola hits rock bottom, but Victoria Police wants her to take on a new role ... as a witness.

Nicola wants to be the best source ever, and she leads police to the biggest target of all: the mafia. Her double life is getting riskier, but she can't stop. This episode charts an addiction and a crash.

Nicola crosses the point of no return and becomes a police informer. She'll represent clients, while passing on the underworld's secrets to Victoria Police.

A drug house burglary smells of police corruption and a police informer is executed.

As the gangland war explodes, both police and criminals start questioning Nicola's allegiances. Where do her loyalties lie?

We meet Nicola Gobbo in a secret location, in hiding, now that her double life as a police informer is out, and she begins telling us her full story.

Lawyer Nicola Gobbo represented some of Australia's most dangerous criminals, all the while secretly working as a police informer. Why did she do it?

More than a year on from their plea for a new coronial inquest, the James brothers get a decision. Will they finally get answers to the burning questions they've carried for 38 years about the murder of their mother? And what about those items Trace has been given that might have DNA on them? Can they identify the killer? We take them to one of the world's best DNA labs, with some of the most sensitive equipment, to find out.

New evidence has been found. So can police test it for a trace of the killer? What happened to crucial documents? And a new confession. It is nearly a year since the James brothers applied for a new coronial inquest into their mum's murder, but the case hangs in legal limbo.

The fall-out from major revelations in the Maria James cold-case continue, as her sons make a desperate plea to the Coroner.

There's a major break in the case, as Trace uncovers a police bungle in the murder of Maria James. But it only serves to throw up more questions than answers, as the James brothers continue their desperate search for justice.

A second person of interest emerges within the church. Rachael Brown investigates their past and discovers a dark and disturbing history.

Since Trace was first released, the ABC has received over 50 emails from the community with leads and tip offs. In this bonus update, reporter Rachael Brown follows up with two women who got in touch to say they saw men acting suspiciously around Maria's bookshop at the time of her murder. Send us your tips: trace@abc.net.au