Evidence related to a possible murder weapon shouldn't have been put before the jury at the trial of Robert Xie, who was convicted of bludgeoning five relatives to death, his appeal has been told.
The trial judge erred in admitting "coincidence" evidence in relation to a folded, blood-soaked piece of cloth found at the crime scene and a "massage device" found at Xie's home, his barrister Tom Quilter said.
After four trials, Xie was found guilty in 2017 of murdering three adults and two children in the bedrooms of their Sydney home in the early hours of July 18, 2009.
Xie's newsagent brother-in-law Min Lin, 45, his wife Lily Lin, 43, the couple's sons Henry, 12, and nine-year-old Terry, and Lily's 39-year-old sister, Irene, suffered horrific head injuries when they were attacked with what the Crown contended to be a hammer like object attached to a rope.
The now 56-year-old Xie is behind bars for the rest of his life and is appealing his convictions on seven grounds in the NSW Court of Criminal Appeal.
On Monday, the fifth hearing day, Mr Quilter said the murder weapon was never located by police nor seen by any witness.
But at trial the Crown successfully applied to adduce "coincidence evidence" asserting similarities between a piece of blood-soaked cloth found in one of the bedrooms, and a folded towel on a homemade massage device found at Xie's home in May 2010.
The Crown had contended the murders were committed with a hammer-like implement and that the blood-soaked piece of cloth was at one time secured to the head of the implement with a red rubber band.
The massage device featured towelling which was folded over a protruding bolt and secured in place with a red rubber band.
Mr Quilter said while the defence agreed Xie constructed the massage device, it very much disputed he constructed a murder weapon.
"If the applicant's construction of the massage device, through tendency or coincidence reasoning, was admissible to prove that he affixed the piece of cloth to the murder weapon, then this would be evidence that the applicant committed the murders," Mr Quilter said.
The defence argued there was no proper foundation for an inference that the piece of cloth was attached to the murder weapon.
Further, the fundamentally different purposes of the two objects - the massage device had a remedial purpose, while the hypothesised murder weapon was used to inflict harm - reduced "the probative value of the coincidence evidence", Mr Quilter said.
He said different types of fabric, which were different sizes, were used in the two objects and no meaningful comparison was able to be made of the two rubber bands, other than they were both red.
The cloth found at the crime scene had been folded twice, while the hand towel on the massage device was folded at least three times.
The appeal is continuing.
Australian Associated Press