Robert Xie murder trial: the blood stains that helped catch a killer.

By court reporter Karl Hoerr

To the naked eye, it looks entirely unremarkable.

A small stain found on the floor of Robert Xie’s North Epping garage, in Sydney’s north-west, almost a year after five members of the Lin family were murdered a short distance away in July 2009.

But this piece of evidence could have been the difference between the 52-year-old being convicted and walking free.

Photographs taken during a police search of the garage in May 2010, publicly released for the first time today, show a ramshackle of old furniture, some pieces stacked on top of others.

They also show a blood stain on the garage floor, which came to be referred to as “stain 91” during Xie’s murder trial.

It was subjected to DNA analysis and prosecutors said it contained a mixture of at least four of the victims’ blood.

It is believed Xie returned to the garage after the murders and failed to notice the stain.

Prosecutors told the jury in his murder trial that on the morning of July 18, 2009, Xie cleaned up his garage.

It was only later that morning that Xie’s wife Kathy Lin found the bodies of the victims after she went to the home of her brother, Epping newsagent Min Lin, who had failed to show up for work.

She was with her husband at the time.

It was not until May 2011 that Xie was arrested and charged.

By a majority of 11 to one, a jury last week found Xie guilty of murdering Mr Lin, his wife Lily, sister-in-law Irene and two young sons Henry and Terry.

All were beaten with what police suspect was a hammer and most also suffered neck compression injuries and asphyxia.

Shoe prints reveal Xie acted alone

The NSW Supreme Court has released a series of exhibits that were tendered during Xie’s six-month trial, including photographs of bloodied shoe prints found on the carpet of the Lin family home.

Those impressions were matched to a particular model of shoe known to have been worn by Xie.

The absence of any other relevant shoe prints meant police could confidently say there was only one killer involved in the crime.

During the trial, Xie’s lawyers claimed the shoe impressions could have been left by a number of different brands.

They also refused to accept that stain 91 was actually blood, and said the DNA could have been transferred to the garage floor in a number of different ways, unrelated to the murders.

Xie participated in a number of police interviews and his wife was also questioned extensively by investigators.

In her triple-0 call, Mrs Lin can be heard speaking in Cantonese, begging her husband to stay with her until police arrive.

But Xie insisted on leaving the murder scene so he could pick up his parents-in-law from their home in Merrylands in Sydney’s west.

Police believe Xie used this time to dispose of the murder weapon.

Featured image: Supplied/Supreme Court of NSW

This post originally appeared on ABC News.