Accused police killer Jason Roberts’ lawyers say transcripts of secret listening devices made by police decades ago are significantly less incriminating when translated by experts.

Mr Roberts is facing a fresh trial over the murders of Sergeant Gary Silk and Senior Constable Rodney Miller in 1998, after a previous conviction was quashed by Victoria’s Court of Appeal earlier in November.

Defence lawyer Peter Matthews says they’ve spent tens of thousands of dollars already having expert linguists redo transcripts of the “indistinct” recordings used in Mr Roberts’ original 2002 trial.

Original recordings were transcribed by police.

“The content is significantly less inculpatory when transcribed by an expert, to the point of not inculpatory at all,” he said in a Supreme Court bail application by Mr Roberts on Thursday.

Justice David Beach will hand down his decision on Thursday afternoon.

In quashing the original jury verdict, the Court of Appeal found it was not inevitable that Mr Roberts would be convicted again, but the case was strong.

Mr Matthews said that was not necessarily the case, when considering the evidence as it would be presented in a fresh trial.

Justice Beach said a trial could begin in late 2021, but Mr Matthews said 2022 was more likely.

The defence team has also spent a significant sum of money on expert scientific reports, including around the evidence about whether there was one or two shooters involved.

Mr Roberts has admitted – and will maintain in a fresh trial – that he was involved in a series of robberies with Bandali Debs, who was also convicted of murdering Sergeant Silk and Senior Constable Miller.

Mr Roberts has always maintained his innocence in the murders. Debs is serving a life sentence and has not appealed.

Mr Matthews said another aspect of the new trial will be the fresh defence evidence about an alibi, from both Mr Roberts and his then-girlfriend Nicole Debs – Debs’ daughter.

He said the fact alone that he had spent 20 years behind bars after a trial “corrupted” by Victoria Police was exceptional enough in itself to justify bail.

Mr Roberts has been in restrictive custody since 2013 and coronavirus restrictions in place since March 2020 had compounded the weight of imprisonment on him, Mr Matthew said.

Prosecutor Ben Ihle SC said there were ultimately three factors for Justice Beach to consider.

“In favour of the grant of bail is clearly the considerable period of time the applicant has already spent in custody,” he said.

But on the other hand he said Mr Roberts was facing extremely serious allegations and their belief it was a strong case.

Mr Roberts denied at his first trial, but has since admitted, that he was involved in 10 burglaries with Debs, that he used a 0.38 handgun in those robberies and he continued to offend with Debs after the officers died.

Mr Ihle acknowledged the time Mr Roberts had spent in custody was significant, but he was coming up against an undeniably strong or powerful prosecution case.

Justice Beach acknowledged that if Mr Roberts was to be convicted and receive the same sentence, he would have have served only a fraction of it.

-AAP