Lian Bin “Robert” Xie is on trial for the murder of Min "Norman" Lin, 45; Mr Lin’s wife, Yun "Lily" Li Lin, 44; their sons Henry, 12, and Terry, 9; and Ms Lin's sister, Yun Bin "Irene" Yin, 39, in Boundary Road, Epping, in the early hours of July 18, 2009. The court heard on Monday that, after being arrested, the 50-year-old was caught in a carefully planned police sting designed to flush out vital information about his involvement in the crime. Crown prosecutor Mark Tedeschi, QC, told the jury that a prison inmate, known as "Witness A", would give evidence about 21 separate conversations he had with Mr Xie over the course of 18 months they spent in neighbouring cells in Long Bay jail from mid-2011. These allegedly included discussions about two plots - both known as 'Plan B' - by which Mr Xie would allegedly frame dead people for the murders by planting their DNA at the crime scene or on a murder weapon. The court heard that Witness A told the accused killer that he had a “contact inside a funeral parlour” called "Harry" who could find a body whose DNA could be put on the murder weapon, the location of which would then be leaked to police.

"Harry" was in fact an undercover police officer. “Witness A told the accused that at the funeral parlour there was a dead body of an Asian male about the right age who was awaiting transportation to China and who had a criminal record for people smuggling," Mr Tedeschi said. "He said that Harry would be able to get the DNA evidence from this deceased person and plant it on the murder weapon." They would then tip off police or the media to the location of the weapon, leading police to discover the deceased man's DNA, thus framing him for the crime. The court heard that when the 50-year-old was committed for trial, he allegedly came up with his own version of the plot.

This allegedly involved Harry finding a deceased person whose first name was the same as that of a man who he believed had been having an affair with Mrs Lin. The DNA of this man would then allegedly be placed on the murder weapon or at the crime scene. But Mr Xie’s barrister, Graham Turnbull, SC, said Witness A was a repeat offender who had “targeted the accused in order to ensure something for himself”. “He is a practised manipulator who stands to gain a lot from giving evidence against the accused,” Mr Turnbull said, referring to the significant discount the informant had been given on his sentence in return for helping police. He put it to the jury that the Crown’s “core proposition” - that Mr Xie had crept into the Lins' home and killed all five of them in the dark on his own and escaped without leaving a trace – was “completely unlikely”.

“Look at him - this man is 170cm tall, 60kg, who was 46 years of age [at the time of the killings],” Mr Turnbull said. “He is not aggressive, not angry, not violent, and there is no evidence he was capable of using this so-called weapon…” “It is the defence case that two or three people committed this crime.” Mr Turnbull's opening address continues on Tuesday.