Body under the bridge: Police tried to trap alleged killer with undercover civilian

CONTENT WARNING: This article refers to suicide.

When a man bumped into a suspected killer in Bega, the suspect had no idea the man was part of a police ploy to get her to admit to her alleged involvement in the death of a young woman whose naked body was found under a bridge on the NSW Far South Coast.

A recently released court decision details how police recruited a civilian to strike up a friendship with Rosemary ‘Rosie’ Priscilla Mackie, who was accused of murdering Marnie-Lee Cave nearly a decade ago. It also reveals a shocking allegation that never made it before a jury.

Campers found Ms Cave’s body in the Bega River below the Mogareeka Bridge, which is just north of the town of Tathra, early in the morning of 14 October 2015.

The 26-year-old had been strangled to death as well as hit on the head with a blunt object, possibly a block splitter.

The investigation resulted in the arrest of then-52-year-old Ms Mackie of Bega later that year. She pleaded not guilty to murder and after two jury trials, was ultimately acquitted.

But part of the case against her involved a civilian undercover operative, and whether or not the alleged admissions she made to this man could be used in a trial were debated in the NSW Supreme Court in 2017.

The tragic case also involved Ms Mackie’s de facto partner, 52-year-old Bernhard ‘Bernie’ Webber, a cleaner who would often smoke cannabis with Ms Cave.

Police raided his home on 20 October 2015 and seized a number of ropes. Mr Webber, who was the last person seen with Ms Cave while she was alive, died by suicide two days later.

That November, police retained the services of an undercover operative, who was not a member of the police force, to try to get admissions from Ms Mackie about Ms Cave’s death.

This man, given the name ‘Michael O’Brien’, had performed similar work for 20 years.

He started his relationship with Ms Mackie in November 2015 by intentionally walking into her and telling her he was a long-time friend of Mr Webber’s who had come to Bega to see if he could help her move to Newcastle to be with her family.

Over lunch and drinks at a local hotel, Ms Mackie allegedly said she was jealous of Ms Cave, who she thought was interfering in her relationship, and allegedly said, “Bernie got rid of Marnie”.

“Over a short space of time, Mr O’Brien was able to develop a friendly relationship with the accused,” Justice Peter Garling said.

Mr O’Brien said Ms Mackie “kept mentioning Bernie all the time, that she’d hear his voice, things like that”, so he took advantage of this, telling her Mr Webber was speaking to him through the “spirit world”.

He told her, “Bernie wants you to tell me what he done”, and that her dead partner would be proud of her for telling the truth.

He also drove her to the Mogareeka Bridge and asked her to reenact what happened to Ms Cave.

“At the bridge it became apparent that the accused was quite confused about what had occurred, and she was seemingly unable to describe accurately what had happened with the deceased’s body,” Justice Garling said.

“On the return trip from Mogareeka Bridge, it was apparent that the accused thought that she was communicating directly with Bernie.”

Mr O’Brien claimed Ms Mackie told him several versions of the alleged murder.

Based on the conversations and secret recordings between the pair, prosecutors alleged Ms Mackie hit Ms Cave with a block splitter at Mr Webber’s house. He allegedly put her in the boot of his car and the couple allegedly strangled her with a rope before driving to the bridge and dropping her into the river.

Police thought Mr Webber was the principal perpetrator of the alleged murder. While Ms Mackie was charged, she was cleared of any criminal wrongdoing when her final jury trial found her not guilty in 2019.

The discussion on Mr O’Brien’s evidence took place in 2017, with Justice Garling ruling it was admissible in the trial, but the publication of the discussion was restricted until August 2024.

However, the judge also ruled other alleged admissions Ms Mackie made were inadmissible, so they never went before a jury.

In this case, it was alleged that after she was arrested, she told Detective Chief Inspector Kevin McNeill, “I didn’t mean it”.

“I hit her in the bathroom with the block splitter; Bernie strangled her with a blue rope,” she allegedly told him.

Ms Mackie allegedly said she was at Mr Webber’s home when he and Ms Cave were “doing cones”.

“I got angry, she is always there getting in the way, she goes to the bathroom and I hit her and then Bernie strangles her with the blue rope,” she allegedly said.

When ruling these alleged comments inadmissible, Justice Garling said the circumstances of the situation meant Ms Mackie thought anything she said to DCI McNeill was “off the record”.

After Ms Cave’s death, her family posted a tribute to her on a local newspaper’s obituary website.

“My heart still aches with sadness, my secret tears still flow, what it means to lose you, no one will ever know,” it reads.

If you or someone you know needs help, you can contact:

Lifeline’s 24-hour crisis support line – 13 11 14
Suicide Call Back Service – 1300 659 467
Kids Helpline – 1800 551 800 or kidshelpline.com.au
MensLine Australia – 1300 789 978 or mensline.org.au