Robert William Broad, of Mayfield, has pleaded not guilty to failing to report a killing and his trial started on Tuesday in Launceston’s Supreme Court.

Mr Clark-Robertson was last seen in July 2016, but his body was not found until April 2017. 

His body was discovered in a shallow grave in the back yard of Mr Broad’s Mayfield home. 

Mr Clark-Robertson and a male and female friend had moved into the spare bedroom of the Mitchell Street residence in the same month Mr Clark went missing, a court heard. 

The remains were forensically examined by Dr Donald Ritchie in Hobart and Mr Clark-Robertson was identified using dental records. 

Dr Ritchie said the body was placed in a fetal position in the grave, with the left side closest to the surface.

An examination of Mr Clark-Robertson’s skull revealed he had three fractures to the back of his head that had features of blunt force trauma, Dr Ritchie said. 

Although his brain had decomposed, Dr Ritchie told the court there was evidence Mr Clark-Robertson haemorrhaged while he was alive.  

Dr Ritchie said the cause of death was undetermined because of how decomposed the body was, but there was a great deal of evidence he did not die of natural causes.  

Tasmania Police Senior Constable Maree Fish told the court forensic officers spent eight hours slowly removing dirt from the area where they believed the body was buried. 

“If you go too quickly you will disturb the skeleton,” she said. 

“Our aim is to take the skeleton out in its completeness.”

The top of Mr Clark’s skull was discovered about 20 centimetres from the surface, Senior Constable Fish said. 

In his opening address, Crown Prosecutor John Ransom said the accused had been told Mr Clark was dead by his male housemate.

The key issue in the state’s case was when the accused discovered the killing, Mr Ransom said. 

In April 2017, Mr Broad was interviewed by police twice and Mr Ransom said the accused made unequivocal admissions he knew Mr Clark was dead. 

But defence lawyer Darrell Grey said the trial was not about when his client was told about the killing or when it was first mentioned.  

“You do need to be concerned about when Robert Broad discovered there was a killing,” Mr Grey told the jury. 

Videos of the accused’s two police interviews were played to the jury.

Mr Broad became emotional when police asked why he hadn’t reported Mr Clark’s death earlier. 

“I don’t know. I thought it wasn’t true,” Mr Broad said. 

“I should’ve done, but I didn’t.”

Mr Broad told the officers he noticed a suspicious patch in his garden when mowing the lawn, so he questioned his male housemate about it. 

“I asked him, ‘is that a graveyard’. He said ‘no’,” Mr Broad said. 

Mr Clark-Robertson’s family, including his father Tim Clark, were in the courtroom on Tuesday. The trial will continue on Wednesday.