A man on trial for three murders told a cellmate he had "roughed up" a Mount Gambier man who was later found dead, a court has been told.
Mildura man Steven Leslie Hainsworth, 49, is on trial in the South Australian Supreme Court charged with the murders of Phyllis Harrison, 71, at Elizabeth South in 1998, Beverley Hanley, 64, at Elizabeth North in 2010 and Stephen Newton, 55, at Mt Gambier in 2011.
The trial sat in Mt Gambier last week, hearing evidence about Mr Newton's alleged murder and visiting his former home, where his body was found on November 4, 2011.
Gavin Kennett on Wednesday told the court he was sharing a cell with Hainsworth at Yatala Labour Prison in Adelaide in 2021.
Asked by prosecutor Martin Hinton KC if he had discussed Mr Newton's murder with Hainsworth, he said the accused had told him he had gone to the victim's house to "get pot".
"He said to me there was a garage sale there and he bought a big TV and DVD player,'' Mr Kennett said via video link from Mt Gambier.
"He said when he got it home, Stephen Newton had left a DVD in there that was child porn and the girl in there looked similar to his daughter and he got angry, he wasn't happy at all.
"He said he went back there and hit him a couple of times, roughed him up … he said he got angry and Steve hit the ground and ... he left there pretty quick. He said (Mr Newton) wasn't moving or anything."
Hainsworth is also charged with the murder of his aunt, Beverley Hanley, the previous year.
Asked if Hainsworth had mentioned his aunt, Mr Kennett said "he said that 'she had a fair bit of money'."
"He said that he'd seen through the window that she had a stash of money," he said.
Denise Rankine, who was an acquaintance of Hainsworth's, said she had overheard the accused speaking about Mr Newton's murder.
"I overheard a few conversations about the TV that was taken, property that was missing. Hainsworth was mainly bragging, 'oh, he pretty much deserved it' and he sold his stuff. He said he sold the TV," she said.
"The murder was on the telly and (Hainsworth) goes: 'that's not how it went down', so I'm thinking 'how would a person know how it went?' The way he said it was very disturbing."
At the start of the trial, prosecutor Amelia Cairney told the court Hainsworth was a drug user who targeted three vulnerable people who were living alone and killed each of them violently while searching for valuables to fund his habit.
Mr Newton was last seen alive on September 24, 2011.
On Wednesday, the court was shown a recording made by police who entered the house while investigating a report Mr Newton was missing.
As well as discovering Mr Newton's badly decomposed body, they seized DVDs marked "porn" and "young girls" and child exploitation material was lfound on them.
The word "Phedfile" was spraypainted on a wall.
The judge-alone trial, before Justice Adam Kimber, continues.
