The robber, who cannot be named, was put in the frame after his friend testified against him, saying he had confessed to the crime.

He is alleged to have walked into the betting agency in December 2009 with his face covered by a beanie and scarf.

The robber was carrying a bag and a sawn-off .22 rifle, which he pointed at the store supervisor and demanded money.

He threw the bag over the glass partition and the worker filled it with roughly $32,000 from two safes and a register.

He wasn't arrested until 2011, after his friend implicated him to help secure himself indemnity from prosecution for other crimes.

"He told me he robbed the place," the friend told the court on Tuesday.

The witness also told police the gun was stashed between the robber's backyard shed and fence.

Police, despite having already searched the property, went back to the home following that tip and found the weapon.

The robber's son also gave evidence that he saw his father shortening a rifle, similar to that used in the robbery.

Defence barrister Shane Gill attempted to discredit his client's friend, the case's key witness, and his evidence about the confession.

He said the gun discovered in his client's backyard "smells like a plant", and accused the witness of lying to secure the indemnity deal with police.

But the prosecution, represented by Mark Fernandez, said the gun had been covered with grass clippings, and would have been hidden from police during their first search.

Mr Fernandez dismissed the defence theory of the planting of the gun, asking the jury why the witness would do anything to threaten the indemnity deal with police.

He said the evidence of the accused's son provided a "powerful link" in the case.

Mr Gill, however, argued it was irrelevant because the son said he saw his father shortening the rifle after the robbery took place.

The trial took place in front of Justice Steven Rares.

The robber will be sentenced at a later date.