Vincent O'Dempsey, 87, on Wednesday needed a hearing aid when he faced Brisbane Magistrates Court for a committal hearing charged with murdering Vincent Raymond Allen.
Mr Allen, a 22-year-old labourer, was last seen in a car at Warwick, southwest of Brisbane, about 5pm on April 18, 1964.
His body has not been found.
Warren McDonald testified he heard from unknown young men at a party in Warwick in the 1990s that O'Dempsey had killed someone.
He later mentioned the conversation to O'Dempsey.
"(O'Dempsey) wasn't saying it was bullshit," Mr McDonald said.
O'Dempsey replied: "You should have heard what those pair of c***s were saying about (you)."
Under cross-examination from defence barrister Patrick Wilson, Mr McDonald said O'Dempsey never said directly he had killed anyone.
Before he disappeared Mr Allen had just given police information about two jewellery store break and enters in southern Queensland.
Mr McDonald said another man talked about O'Dempsey "knocking off jewellery stores".
"He said 'no one gives evidence against O'Dempsey'," Mr McDonald testified.
Mr McDonald said O'Dempsey had spoken to him about the notorious 1990s Snowtown murders in South Australia, where bodies were placed in barrels and left in an abandoned bank vault.
"Vince said 'the bastards used the wrong acid'," Mr McDonald said.
"He said you had to use a steel bathtub to leave no evidence."
Mr McDonald said he was "horrified" but O'Dempsey never said he had disposed of a body.
Earnest Bradford testified he had been preparing for a football match with O'Dempsey in 1964 when an unknown man spoke to him.
"The other man told me 'that mad bastard over there threw someone in the wall of the dam last night'," Mr Bradford said.
He said he assumed O'Dempsey must have been working on constructing the dam wall in southern Queensland.
"(O'Dempsey) never said a word, he just had a stupid grin on his face," Mr Bradford said.
The case's investigator, Detective Sergeant Brett Cooper, testified he had a theory about what happened to Mr Allen.
"He is likely buried somewhere in the Warwick area," Det Sgt Cooper said.
"I would think that being in the dam wall would be highly unlikely."
Police had been unable to use new techniques to scan within the dam wall due to technical issues, Det Sgt Cooper said.
O'Dempsey was arrested and charged in August 2019 with Mr Allen's murder.
Mr Wilson on Wednesday conceded to Deputy Chief Magistrate Anthony Gett that O'Dempsey had a prima facie case to answer.
Mr Gett ordered that O'Dempsey be remanded in custody to face trial at a later date in Brisbane Supreme Court.
Asked by Mr Gett if he wanted to enter a plea or say anything in response, O'Dempsey said: "No, Your Honour."
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