Vincent O'Dempsey has pleaded not guilty to the murders of Barbara McCulkin and her daughters Vicki and Leanne.
Vincent O'Dempsey has pleaded not guilty to the murders of Barbara McCulkin and her daughters Vicki and Leanne. Nine News

'She had to be dealt with'

"SHE (Barbara McCulkin) had to be dealt with, leave it at that."

This is the recent "murder confession" Vincent O'Dempsey allegedly made to a man he met in prison on remand.

The 79-year-old Warwick resident on Tuesday pleaded not guilty to the murder of Mrs McCulkin and her daughters Vicki, 13, and Leanne, 11.

He has also pleaded not guilty in the Brisbane Supreme Court to one count of deprivation of liberty.

The McCulkins were last seen alive on January 16, 1974, at their Highgate Hill home.

In his opening address, Crown prosecutor David Meredith said Mr O'Dempsey talked about the McCulkins with a prisoner in January while waiting for the trial to start.

Mr Meredith said that the confessions were made after the prisoner who cannot be named asked about the family's disappearance.

"Look in those days, you got paid to do a job," Mr O'Dempsey allegedly told the inmate who wrote the accused's comments on scraps of paper.

"I never laid a hand on the two kids ... Shorty did.

"She (Mrs McCulkin) had to be dealt with, leave it at that."

Mr O'Dempsey also "confessed" to Warwick resident Warren McDonald and Mr O'Dempsey's former lover Kerri Scully about the crimes, Mr Meredith said.

"You need a notch on your gun," Mr O'Dempsey allegedly told Mr McDonald in the late 1990s.

"You need a kill. When I was your age I had several notches on my gun."

Mr O'Dempsey made the comments while Mr McDonald was helping him cultivate marijuana on the Southern Downs.

"He (Mr O'Dempsey) was telling McDonald that he needed to kill people (to gain respect)," Mr Meredith told the jury.

"(Mr O'Dempsey told Mr McDonald) that he killed the McCulkins and that Shorty was nothing but a rapist."

Mr Meredith said Mr O'Dempsey claimed the McCulkins' bodies would not be found.

"They'll never get me because they'll never find the bodies," Mr O'Dempsey allegedly told Mr McDonald.

Mr Meredith said the circumstances surrounding the confessions were different but there was "one common thread".

"Namely that the three people who he made the confessions to were in a criminal milieu - they were people you might expect O'Dempsey to trust to not talk to police," Mr Meredith said.

The trial before Justice Peter Applegarth continues.


Jury told murder accused 'threatened two witnesses'

VINCENT O'Dempsey allegedly said two witnesses would "be killed" if they gave evidence at his murder trial.

Mr O'Dempsey allegedly told a prisoner - who cannot be named - that there were only two people who could give evidence against him.

Warren McDonald, with whom he grew drugs in the late 1990s, and Mr O'Dempsey's former lover Kerri Scully are listed to take the witness box in Mr O'Dempsey's murder trial in the next two weeks.

The two witnesses would talk about Mr O'Dempsey "confessing" to killing Barbara, Vicki and Leanne McCulkin, Crown Prosecutor David Meredith told Brisbane Supreme Court on Tuesday.

"On the tape (recorded by the prisoner) O'Dempsey says 'they're off', meaning they will be killed," Mr Meredith said.

Mr Meredith said the McCulkins might have been murdered because Mrs McCulkin and one of her daughters appeared to have knowledge of the Whiskey Au Go Go fire that killed 15 people in 1973.

Two men were convicted over the killer blaze but "it did not stop speculation about the involvement of others", the prosecutor told the jury of 15 people, including three reserves.

"It may not seem much of a motive to kill three people, but there is never a good motive to do that," he said.

Timeline of events

6.30pm, Jan 16, 1974: Janet Gayton sees two men called "Vince" and "Shorty" at the Highgate Hill home of Barbara McCulkin and her daughters Leanne and Vicki. Leanne and Vicki go across the road to Janet's house for a party. Leanne leaves around 7.30pm and Vicki leaves around 10.15pm.

Jan 17: Vicki and Leanne fail to meet Janet and her sister for a play date; Mrs McCulkin's estranged husband Billy McCulkin searches for his missing family. He speaks to Vincent O'Dempsey and Garry Reginald 'Shorty' Dubois, asking them if they were with his family the previous evening.

Jan 18, 1974: Mr McCulkin reports the McCulkins missing.

May 2, 1917: Mr O'Dempsey goes on trial for the murders of the McCulkins. He has pleaded not guilty.